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Mölders, Nicole. "Concepts for coupling hydrological and meteorological models." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-215597.
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Earth system modeling, climate modeling, water resource research as well as integrated modeling (e.g., climate impact studies) require the coupling of hydrological and meteorological models. The paper presents recent concepts on such a coupling. It points out the difficulties to be solved, and provides a brief overview on recently realized couplings. Furthermore, a concept of a hydrometeorological module to couple hydrological and meteorological models is introducedWasserresourcenforschung, Erdsystem- und Klimamodellierung sowie integrierte Modellierung (z.B. Klimafolgenforschung) erfordern das Koppeln von hydrologischen und meteorologischen Modellen. Dieser Artikel präsentiert Konzepte für eine solche Kopplung. Er zeigt die zu lösenden Schwierigkeiten auf und gibt einen kurzen Überblick über bisher realisierte Kopplungen. Ferner stellt er ein Konzept für einen hydrometeorologischen Moduls zur Kopplung von hydrologischen mit meteorologischen Modellen vor
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Mölders, Nicole. "Concepts for coupling hydrological and meteorological models." Wissenschaftliche Mitteilungen des Leipziger Instituts für Meteorologie ; 22 = Meteorologische Arbeiten aus Leipzig ; 6 (2001), S. 1-15, 2001. https://ul.qucosa.de/id/qucosa%3A14140.
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Earth system modeling, climate modeling, water resource research as well as integrated modeling (e.g., climate impact studies) require the coupling of hydrological and meteorological models. The paper presents recent concepts on such a coupling. It points out the difficulties to be solved, and provides a brief overview on recently realized couplings. Furthermore, a concept of a hydrometeorological module to couple hydrological and meteorological models is introduced.Wasserresourcenforschung, Erdsystem- und Klimamodellierung sowie integrierte Modellierung (z.B. Klimafolgenforschung) erfordern das Koppeln von hydrologischen und meteorologischen Modellen. Dieser Artikel präsentiert Konzepte für eine solche Kopplung. Er zeigt die zu lösenden Schwierigkeiten auf und gibt einen kurzen Überblick über bisher realisierte Kopplungen. Ferner stellt er ein Konzept für einen hydrometeorologischen Moduls zur Kopplung von hydrologischen mit meteorologischen Modellen vor.
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Abdulla, Fayez Ahmad. "Regionalization of a macroscale hydrological model /." Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/10151.
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Reusser, Dominik, Theresa Blume, Bettina Schaefli, and Erwin Zehe. "Analysing the temporal dynamics of model performance for hydrological models." Universität Potsdam, 2009. http://opus.kobv.de/ubp/volltexte/2010/4511/.
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The temporal dynamics of hydrological model performance gives insights into errors that cannot be obtained from global performance measures assigning a single number to the fit of a simulated time series to an observed reference series. These errors can include errors in data, model parameters, or model structure. Dealing with a set of performance measures evaluated at a high temporal resolution implies analyzing and interpreting a high dimensional data set. This paper presents a method for such a hydrological model performance assessment with a high temporal resolution and illustrates its application for two very different rainfall-runoff modeling case studies. The first is the Wilde Weisseritz case study, a headwater catchment in the eastern Ore Mountains, simulated with the conceptual model WaSiM-ETH. The second is the Malalcahuello case study, a headwater catchment in the Chilean Andes, simulated with the physicsbased model Catflow. The proposed time-resolved performance assessment starts with the computation of a large set of classically used performance measures for a moving window. The key of the developed approach is a data-reduction method based on self-organizing maps (SOMs) and cluster analysis to classify the high-dimensional performance matrix. Synthetic peak errors are used to interpret the resulting error classes. The final outcome of the proposed method is a time series of the occurrence of dominant error types. For the two case studies analyzed here, 6 such error types have been identified. They show clear temporal patterns, which can lead to the identification of model structural errors.
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Davison, Bruce. "Snow Accumulation in a Distributed Hydrological Model." Thesis, University of Waterloo, 2004. http://hdl.handle.net/10012/793.
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The cryosphere is defined as the portions of the earth where water is in solid form. It represents a very important part of the hydrologic cycle, affecting ecological, human and climate systems. A number of component models describing the energy and mass balances of a snowpack have been developed and these component models are finding their way into watershed models and land surface schemes. The purpose of this thesis is to examine the incorporation of a number of snow processes in the coupled land-surface-hydrological model WATCLASS.
The processes under consideration were mixed precipitation, variable fresh snow density, maximum snowpack density, canopy interception and snow-covered area (SCA). The first four of these processes were based on similar work done by Fassnacht (2000) on a watershed in Southern Ontario. In the case of this thesis, the work was completed on a basin in Northern Manitoba. A theory of the relationship between snow-covered area and average snow depth was developed and an algorithm was developed to implement this theory in WATCLASS. Of the five snow processes considered, mixed precipitation was found to have the greatest impact on streamflow while the new canopy interception algorithm was found to have the greatest impact on sensible and latent heat fluxes. The development of a new relationship between SCA and average snow depth was found to have a minimal impact in one study case, but a significant impact on the sensible and latent heat fluxes when snow fell on a pack that had begun to melt and was partially free of snow. Further study of these snow processes in land-surface-hydrologic models is recommended.
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Kim, JongKwan. "The Calibration and Uncertainty Evaluation of Spatially Distributed Hydrological." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/1437.
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In the last decade, spatially distributed hydrological models have rapidly advanced with the widespread availability of remotely sensed and geomatics information. Particularly, the areas of calibration and evaluation of spatially distributed hydrological models have been attempted in order to reduce the differences between models and improve realism through various techniques. Despite steady efforts, the study of calibrations and evaluations for spatially distributed hydrological models is still a largely unexplored field, in that there is no research in terms of the interactions of snow and water balance components with the traditional measurement methods as error functions. As one of the factors related to runoff, melting snow is important, especially in mountainous regions with heavy snowfall; however, no study considering both snow and water components simultaneously has investigated the procedures of calibration and evaluation for spatially distributed models. Additionally, novel approaches of error functions would be needed to reflect the characteristics of spatially distributed hydrological models in the comparison between simulated and observed values. Lastly, the shift from lumped model calibration to distributed model calibration has raised the model complexity. The number of unknown parameters can rapidly increase, depending on the degree of distribution. Therefore, a strategy is required to determine the optimal degree of model distributions for a study basin. In this study, we will attempt to address the issues raised above. This study utilizes the Research Distributed Hydrological Model (HL-RDHM) developed by Hydrologic Development Office of the National Weather Service (OHD-NWS). This model simultaneously simulates both snow and water balance components. It consists largely of two different modules, i.e., the Snow 17 as a snow component and the Sacramento Soil Moisture Accounting (SAC-SMA) as a water component, and is applied over the Durango River basin in Colorado, which is an area driven primarily by snow. As its main contribution, this research develops and tests various methods to calibrate and evaluate spatially distributed hydrological models with different, non-commensurate, variables and measurements. Additionally, this research provides guidance on the way to decide an appropriate degree of model distribution (resolution) for a specific water catchment.
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Picco, Robert C. "A comparative study of flow forecasting in the Humber River Basin using a deterministic hydrologic model and a dynamic regression statistical model." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ34219.pdf.
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Howes, S. "A mathematical hydrological model for the ungauged catchment." Thesis, University of Bristol, 1985. http://hdl.handle.net/1983/1affdf54-f3d2-4dbe-83b0-836695ef0c8e.
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In geographical hydrology the~e has been more interest in scientific rather than in practical application of mathematical models of catchment hydrology. This thesis emphasizes the importance of examining the potential of developments in scientific research programmes for practical hydrological applications, and in particular provides discussion upon the following five issues: 1 The application of hydrological models to ungauged catchments where no historical streamflow record is available for calibration. 2 The potential of hydrological models for routine and operational application. This application limits the data and computer resources which are available for use. 3 The development and application of a thorough model evaluation strategy which examines the suitability of a model in the context of a specific application requirement. 4 The selection of a conceptually sound model structure. S The development and evaluation of a suitable methodology for the incorporation of the spatial variability of catchments into hydrological" models. To provide a basis for the discussion of these five issues, this thesis provides the details of the modification of a currently used hydrological model, RYMO. The modification of this model involves the replacement of the empirical curve number model for runoff derivation with a physically based parameter infiltration model. A number of comparisons of HYMO and the modified version, HYM02, indicates that conceptual, parameter estimation, prediction, and sensitivity improvements have indeed been secured by the development of the modified model.
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Ishak, Asnor Muizan. "Hydrological simulation aided by numerical weather prediction model." Thesis, University of Bristol, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.559471.
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In many water resources and hydrological projects, it is not always possible to get access to in-situ long-term time series weather measurements, especially for ungauged catchments. Even with gauged catchments, it is common that only rain gauge and river level data are available; other weather variables such as solar radiation, wind speed, surface temperature, surface air pressure and relative humidity are usually missing and if available are generally not in continuous form. These weather variables are basic building blocks of the global hydrological cycle that includes evapotranspiration (ET 0) and runoff estimation. The ET 0 and runoff can be estimated from the Penman-Monteith equation and rainfall runoff modeling respectively. This thesis explored a potential application of downscaled global reanalysis weather data using Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model 5 (MMS). MMS is able to downscale the global weather data down to a much finer resolution in space and time for use in local hydrological investigations. The exploration of downscaling the ERA-40 reanalysis data to the Brue catchment in Southwest England and the assessment of the relevant weather variables in comparison with those measured at the ground was described in the thesis. However, there is a problem in using these selected weather variables in hydrological processes due to uncertainties obtained from the mesoscale modelling. Therefore, this thesis focused on the improvement of the weather variables from the dynamical downscaling and statistical modeling. The improvement of dynamic downscaling with the MMS cumulus parameterization schemes (CPSs) by changing the horizontal and vertical resolutions are presented in this thesis for rainfall estimation. Meanwhile, the error correction with statistical models is an attempt to hybridize MMS with two regression models ( the multiple linear regression (MLR) and the nonlinear regression (NLR)) and two artificial intelligence systems (the artificial neural networks (ANNs) and the support vector machines (SVMs)). This exploration is to tackle the errors between the MMS downscaled and observed data in addition to other MMS derived hydro- meteorological parameters. The hold-out validation with a forward selection method was employed as an input variable selection procedure to examine the model generalization errors in these statistical models. Upon the implementation of the error correction technique of weather variables, a comparative study of runoff simulation via the PDM model was completed between the MMS downscaled, corrected and observed data. This thesis also presents a sensitivity analysis of six weather variables to ET 0 estimation and runoff simulation through various combinations of the Penrnan-Monteith equation and Probability Distributed Model (PDM}inputs. Finally, by this assessment of several case studies in this thesis, it has shown that the enhanced MMS modeling scheme with the correction approaches substantially improves the forecasted weather variables over the study area which is important for the hydrological processes.
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Tjia, Dewi. "Statistical Methods for History Matching of Hydrological Model." Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/57347.
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Four history matching methods were used to calibrate the parameters of the LUCICAT model for three catchments in Western Australia. The methods used were ant colony optimization (ACOR and DACOR), Robust Parameter Estimation and Gauss Levenberg Marquadt. These methods were applied directly and indirectly, and in the latter case multidimensional Kriging and artificial neural networks were used to build proxy models for LUCICAT. All HM methods performed favourably well.
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Wood, Andrew W. "Using climate model ensemble forecasts for seasonal hydrologic prediction /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/10205.
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Zhang, Hongbin. "Urban flood simulation by coupling a hydrodynamic model with a hydrological model." Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/2797.
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This work introduces a new integrated flood modelling tool in urban areas by coupling a hydrodynamic model with a hydrological model in order to overcome the drawbacks of each individual modelling approach, i.e. high computational costs usually associated with hydrodynamic models and less detailed physical representations of the underlying flow processes corresponding to hydrological models. Crucial to the simulation process is to first divide the catchment hydraulic and hydrological zones where the corresponding model is then applied. In the hydrological zones that have more homogeneous land cover and relatively simple topography, a conceptual lumped model is applied to obtain the surface runoff, which is then routed by a group of pre-acquired ‘unit hydrographs’ to the zone border, for high-resolution flood routing in the hydraulic zones with complex topographic features, including roads, buildings, etc. In hydraulic zones, a full 2D hydrodynamic model is applied to provide more detailed flooding information e.g. water depth, flow velocity and arrival time. The new integrated flood modelling tool is validated in Morpeth, the North East of England by reproducing the September 2008 flood event during which the town was severely inundated following an intense rainfall event. Moreover, the coupled model is investigated and evaluated according to the effects from temporal and spatial resolutions, friction, rainfall, infiltration, buildings and coupling methods. In addition, the model is also employed to implement flood damage estimations with different scenarios of the upstream storage and flood defences in the town centre. Whilst producing similar accuracy, the new model is shown to be much more efficient compared with the hydrodynamic model depending on the hydrological zone percentage. These encouraging results indicate that the new modelling tool could be robust and efficient for practitioners to perform flood modelling, damage estimation, risk assessment and flood management in urban areas and large-scale catchments.
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Acharya, Gayatri. "Hydrological-economic linkages in water resource management." Thesis, University of York, 1998. http://etheses.whiterose.ac.uk/10809/.
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Lewarne, Mireille. "Setting up ArcSWAT hydrological model for the Verlorenvlei catchment." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1806.
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Thesis (MA (Geography and Environmental Studies))--University of Stellenbosch, 2009.Agricultural production has become vital to the Sandveld, of which Verlorenvlei is a part, in terms of both economic growth and food security. It is well documented as an area under threat of severe natural resource depletion if it is not well managed with sustainability in mind. Agricultural production, other human-driven development and the survival of the local ecosystems compete for the limited water resources. This study uses the SWAT hydrological model to simulate the transport of water through the catchment area. ArcSWAT, a third-party software extension to ArcGIS, is used as an interface between ArcGIS and the SWAT model. Spatial data (DEM, soil and landuse) is used in the preprocessing phase and fed into the SWAT model through the interface. Daily climate data were sourced and prepared according to the SWAT model’s input requirements. Considerable effort was required to fill temporal and spatial gaps in available climate data, and to infer certain unmeasured climate variables from other measurements (e.g. infer solar radiation from daylight hours, time of the year and latitude). The SWAT hydrological model was then run. The model results compared favourably to measured flow data. The study recommends building on from this first step using the SWAT hydrological model to simulate future land use scenarios for the catchment area.
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Lewis, Elizabeth Ann. "A robust multi-purpose hydrological model for Great Britain." Thesis, University of Newcastle upon Tyne, 2016. http://hdl.handle.net/10443/3290.
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Robust numerical models are an essential tool for informing ood and water management and policy around the world. Physically-based hydrological models have traditionally not been used for such applications due to prohibitively large data, time and computational resource requirements. Given recent advances in computing power and data availability, this study creates, for the rst time, a robust, physically-based hydrological modelling system for Great Britain using the SHETRAN model and national datasets. Such a model has several advantages over less complex systems. Firstly, compared with conceptual models, a national physically-based model is more readily applicable to ungauged catchments, in which hydrological predictions are also required. Secondly, the results of a physically-based system may be more robust under changing conditions such as climate and land cover, as physical processes and relationships are explicitly accounted for. Finally, a fully integrated surface and subsurface model such as SHETRAN o ers a wider range of applications compared with simpler schemes, such as assessments of groundwater resources, sediment transport and ooding from multiple sources. In order to develop a national modelling system based on SHETRAN, a large array of data for the whole of Great Britain and the period 1960-2006 has been integrated into a framework that features a new, user-friendly graphical interface, which extracts and prepares the data required for a SHETRAN simulation of any catchment in Great Britain. This has vastly reduced the time it takes to set up and run a model from months to seconds. Structural changes have also been incorporated into SHETRAN to better represent lakes, handle pits in elevation data and accept gridded meteorological inputs. 306 catchments spanning Great Britain were then modelled using this system. The standard con guration of this system performs satisfactorily (NSE > 0.5) for 72% of catchments and well (NSE > 0.7) for 48%. Many of the remaining 28% of catchments that performed relatively poorly (NSE < 0.5) are located in the chalk in the south east of England. As such, the British Geological Survey 3D geology model for Great Britain (GB3D) has been incorporated for the rst time in any hydrological model to pave the way for improvements to be made to simulations of catchments with important groundwater regimes. This coupling has involved development i of software to allow for easy incorporation of geological information into SHETRAN for any model setup. The addition of more realistic subsurface representation following this approach is shown to greatly improve model performance in areas dominated by groundwater processes. The sensitivity of the modelling system to key inputs and parameters was tested, particularly with respect to the distribution and rates of rainfall and potential evapotranspiration. As part of this, a new national dataset of gridded hourly rainfall was created by disaggregating the 5km UK Climate Projections 2009 (UKCP09) gridded daily rainfall product with partially quality controlled hourly rain gauge data from over 1300 observation stations across the country. Of the sensitivity tests undertaken, the largest improvements in model performance were seen when this hourly gridded rainfall dataset was combined with potential evapotranspiration disaggregated to hourly intervals, with 61% of catchments showing an increase in NSE as a result of more realistic sub-daily meteorological forcing. Additional sensitivity analysis revealed that the slight over-estimation of runo using the initial model con guration which has a median water balance bias of 5% was reduced in 62% of catchments by increasing daily potential evapotranspiration rates by 5%. Similarly, model performance was also found to improve by universally decreasing rainfall rates slightly, which together indicate the possibility of slight under-estimation of potential evapotranspiration derived from available data. In addition to extensive sensitivity testing, the national modelling system for Great Britain has also been coupled with the UKCP09 spatial weather generator to demonstrate the capability of the system to conduct climate change impact assessments. A set of 100 simulations for each of 20 representative catchments across the country were processed for a medium emissions scenario in the 2050s, in order to establish and demonstrate the methodology for conducting such an assessment. The results of these initial simulations suggest that higher potential evapotranspiration rates, combined with modest increases in rainfall under this climate change projection, lead to a general decrease in mean annual river ows. Changes in mean annual ow across the country vary between -26% to +8%, with the biggest reductions in ow found in the south of England and modest increases in runo across Scotland. This work represents a step-change in how the physically-based hydrological model SHETRAN can be used. Not only has this project made SHETRAN much easier to use on its own, but the model can now also be used in conjunction with external applications such as the UKCP09 spatial weather generator and GB3D. This means that the modelling system has great potential to be used as a resource at national, regional and local scales in an array of di erent applications, including climate change impact assessments, land cover change studies and integrated assessments of groundwater and surface water resources.
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Chun, Kwok Pan. "Statistical downscaling of climate model outputs for hydrological extremes." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/6972.
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Changing climate poses an unprecedented challenge for hydrology. The quantification of knowledge on occurrence, circulation and distribution of the waters of the Earth becomes increasingly complex under climate projections because of uncertain effects due to anthropogenic emissions. Traditional understanding of the hydrological cycle needs to be re-examined, and new tools and frameworks for modelling hydrological series with non-stationary characteristics are required for assessing climate change impacts. The aims of this thesis are to (i) understand the relationship between climate change and hydrology at a catchment scale and (ii) develop tools to support climate change adaptation and mitigation. To achieve the aims, this thesis employs a stochastic rainfall model based on generalised linear models (GLMs) to downscale information from regional and global climate models for projecting drought conditions and annual rainfall extremes. Using a state space approach, important global circulation variables for catchment drought characteristics in the Midlands and South East of England are investigated. For annual rainfall extremes, a new approach for studying rainfall simulation series ensemble is proposed based on extreme value theory. Using a statistical modelling methodology related to GLMs, a novel potential evaporation model has been put forward and evaluated. In UK catchment scale application, the results provide insight into possible changes and implications in the shift of rainfall and drought patterns under scenarios of climate in the 2080s. The quality of potential evaporation estimation is shown to be sensitive to the interrelationship of global climate variables. For monthly maxima of potential evaporation, the projected change is high in the southern UK (~25%) but is low in the northern UK (~0%). Furthermore, 2080s streamflows have also been projected. The results show that uncertainty in streamflow projections depend on which GCMs and RCMs are used. Overall, this dissertation provides improved methods for further development in understanding our non-stationary water cycle.
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Camacho, Luis Alejandro. "Development of a hierarchical modelling framework for solute transport under unsteady flow conditions in rivers." Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369124.
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Ding, Deng. "An integrated modeling framework of socio-economic, biophysical, and hydrological processes in Midwest landscapes: remote sensing data, agro-hydrological model, and agent-based model." Diss., University of Iowa, 2014. https://ir.uiowa.edu/etd/1840.
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Intensive human-environment interactions are taking place in Midwestern agricultural systems. An integrated modeling framework is suitable for predicting dynamics of key variables of the socio-economic, biophysical, hydrological processes as well as exploring the potential transitions of system states in response to changes of the driving factors. The purpose of this dissertation is to address issues concerning the interacting processes and consequent changes in land use, water balance, and water quality using an integrated modeling framework. This dissertation is composed of three studies in the same agricultural watershed, the Clear Creek watershed in East-Central Iowa.
In the first study, a parsimonious hydrologic model, the Threshold-Exceedance-Lagrangian Model (TELM), is further developed into RS-TELM (Remote Sensing TELM) to integrate remote sensing vegetation data for estimating evapotranspiration. The goodness of fit of RS-TELM is comparable to a well-calibrated SWAT (Soil and Water Assessment Tool) and even slightly superior in capturing intra-seasonal variability of stream flow. The integration of RS LAI (Leaf Area Index) data improves the model's performance especially over the agriculture dominated landscapes. The input of rainfall datasets with spatially explicit information plays a critical role in increasing the model's goodness of fit.
In the second study, an agent-based model is developed to simulate farmers' decisions on crop type and fertilizer application in response to commodity and biofuel crop prices. The comparison between simulated crop land percentage and crop rotations with satellite-based land cover data suggest that farmers may be underestimating the effects that continuous corn production has on yields (yield drag). The simulation results given alternative market scenarios based on a survey of agricultural land owners and operators in the Clear Creek Watershed show that, farmers see cellulosic biofuel feedstock production in the form of perennial grasses or corn stover as a more risky enterprise than their current crop production systems, likely because of market and production risks and lock in effects. As a result farmers do not follow a simple farm-profit maximization rule.
In the third study, the consequent water quantity and quality change of the potential land use transitions given alternative biofuel crop market scenarios is explored in a case study in the Clear Creek watershed. A computer program is developed to implement the loose-coupling strategy to couple an agent-based land use model with SWAT. The simulation results show that watershed-scale water quantity (water yield and runoff) and quality variables (sediment and nutrient loads) decrease in values as switchgrass price increases. However, negligence of farmers risk aversions towards biofuel crop adoption would cause overestimation of the impacts of switchgrass price on water quantity and quality.
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Vilariño, Daniel R. "Hydrologic calibration of the Cub Run Watershed using the PC version of the Hydrological Simulation Program - FORTRAN (HSPF)." Thesis, Virginia Tech, 1996. http://hdl.handle.net/10919/44438.
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The Hydrological Simulation Program - FORTRAN (HSPF) in its personal computer version, release 10.10, was used to perform the hydrological simulation of a sub-watershed of the Occoquan River drainage basin. The sub-watershed selected was the Cub Run Watershed located in the northern area of the Occoquan River catchment. A model in the form of a User Control Input (UCI) file was prepared. The Cub Run Watershed was analyzed considering its geological, edaphic and weather characteristics, and segmented accordingly. The model was calibrated to adjust simulated results to observed data. Several calibration runs were executed and a final run was done considering a further segmented watershed. The simulation results were good even when not all the desired data could be found. The annual percent difference between the best calibration run and the observed results was 21.28%. The ten-month percent difference, excluding June and July, was 5.82 %. The first value is a fair result for hydrologic calibration, the second value is an excellent result for the same type of calibration. Additional segmentation did not further improve the results obtained during the best calibration run. Differences in the calibration when considering just a pervious segment or two segments (one pervious and one impervious) could be noted, indicating the importance of considering impervious surfaces for the simulation. HSPF reacted quite logically to variations in the calibration parameters and the results from those variations could be predicted beforehand. In summary, the PC version of HSPF was demonstrated to be a good management tool for the hydrological simulation of this watershed.
Master of Science
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Horner, Ivan. "Design and evaluation of hydrological signatures for the diagnostic and improvement of a process-based distributed hydrological model." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALU014.
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L’évaluation des modèles hydrologiques est généralement basée sur des comparaisons des séries de débit observées et simulées à l’aide de critères de performance tels que le Nash-Sutcliffe Efficientcy. Bien que cette approach fournisse des mesures pertinentes de la performance prédictive d’un modèle, elle ne fournit que très peu d’informations sur les raisons d’une bonne ou d’une mauvaise performance. Gupta et al. (2008) ont proposé d’utiliser plutôt des signatures hydrologiques, des indicateurs qui caractérisent le comportement d’un bassin versant. Étant donné que les signatures hydrologiques peuvent être liées aux processus hydrologiques, la comparaison des signatures hydrologiques observées et simulées permet l’évaluation du modèle tout en offrant des diagnostics, i.e. des indications sur les processus hydrologiques qui y sont bien ou mal représentés.Dans cette thèse de doctorat, nous nous concentrons sur l’interprétation et le pouvoir diagnostique des signatures hydrologiques et comment celles-ci peuvent être utilisées pour guider l’amélioration d’un modèle distribué. Nous présentons la construction d’un jeu de signatures hydrologiques, utilisant uniquement des données largement disponibles – précipitations, débit et température de l’air – pour caractériser le fonctionnement hydrologique de 4 sous-bassins versants (Sud-Est de la France) et 10 bassins versants de montagne à influence nival (Southern Sierra, Californie, États-Unis). Des signatures hydrologiques existantes et des nouvelles sont sélectionnées et/ou développées. Collectivement, elles permettent de caractériser le comportement de bassins versants dans une grande variété de contextes hydro-climatiques. En nous concentrant sur les processus de neige, des mesures de neige supplémentaires nous permettent d’évaluer la pertinence des signatures hydrologiques dédiées aux processus nivaux. Par ailleurs, le modèle J2000 est déployé sur le bassin versant de l’Ardèche et une analyse de sensibilité est réalisée afin de comprendre comment les signatures hydrologiques sont liées aux paramètres du modèle. Cela nous permet de déterminer la façon dont elles doivent être interprétées dans le contexte du modèle J2000 de l’Ardèche et permet l’évaluation de leur pouvoir diagnostic. Enfin, en combinant les résultats de l’analyse de sensibilité avec des comparaisons entre signatures observées et simulées, nous entreprenons un diagnostic approfondi du modèle afin de dériver et tester des recommandations pour son amélioration. Nous identifions des déficiences du modèle, principalement liées au stockage de l’eau souterraine et des sols, mettant en évidence des problèmes de représentation spatiale des propriétés géologiques et pédologiquesThe evaluation of hydrological models is typically based on comparisons of observed and sim-ulated streamflow time series using performance metrics such as the Nash-Sutcli˙e Eÿciency. Although it provides relevant measures of the predictive performance of a model, this type of approach provides very little information on the reasons behind good or bad performance. Instead, Gupta et al. (2008) proposed to use hydrological signatures which are indicators that characterize catchment behaviors. Because they can be related to hydrological processes, using them when comparing observation with simulation enable the evaluation of the model while o˙ering diagnostics, i.e. indications on the hydrological processes that are well or badly repre-sented in the model.In this PhD thesis, we focus on the interpretations and diagnostic power of hydrological signatures and how they can be used to guide the improvement of a distributed model. We present the building of a set of hydrological signatures, using only widely available data – pre-cipitation, streamflow and air temperature – to characterize the hydrological functioning of 4 Ardèche sub-catchments (South East of France) and 10 snow dominated catchments of the Southern Sierra mountains (California, USA). Already existing and new hydrological signatures are selected and/or designed. Collectively, they can characterize catchment behavior in a wide variety of hydro-climatic contexts. We demonstrate the value of additional snow measurements to evaluate the information content of snow dedicated hydrological signatures. In the context of the Ardèche catchment, we set up the J2000 distributed model and use a sensitivity analysis to understand how the hydrological signatures are linked to the model parameters. This provides insights into how they are to be interpreted in the context of the J2000 Ardèche model and allows the assessment of their diagnostic power. Finally, combining the results of the sensi-tivity analysis with comparisons between observed and simulated hydrological signatures, we undertake an in-depth diagnostic of the model to provide and test recommendations for its improvement. Deficiencies of the model functioning are identified, mainly related to soil and groundwater storage and fluxes, highlighting issues in the spatial representation of soil and geological properties
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Tetsoane, S. T., Y. E. Woyessa, and W. A. Welderufael. "Evaluation of the SWAT model in simulating catchment hydrology : case study of the Modder River Basin." Interim : Interdisciplinary Journal, Vol 13, Issue 3: Central University of Technology Free State Bloemfontein, 2013. http://hdl.handle.net/11462/313.
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Published ArticleThis paper presents the set-up and the performance of the SWAT model in the Modder River Basin. Two techniques widely used, namely quantitative statistics and graphical techniques, in evaluating hydrological models were used to evaluate the performance of SWAT model. Three quantitative statistics used were, Nash-Sutcliffe efficiency (NSE), present bias (PBIAS), and ratio of the mean square error to the standard deviation of measured data (RSR). The performance of the model was compared with the recommended statistical performance ratings for monthly time step data. The model performed well when compared against monthly model performance ratings during calibration and validation stage.
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Fang, Yuan-Hao, Xingnan Zhang, Chiara Corbari, Marco Mancini, Guo-Yue Niu, and Wenzhi Zeng. "Improving the Xin'anjiang hydrological model based on mass–energy balance." COPERNICUS GESELLSCHAFT MBH, 2017. http://hdl.handle.net/10150/625180.
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Conceptual hydrological models are preferable for real-time flood forecasting, among which the Xin'anjiang (XAJ) model has been widely applied in humid and semi-humid regions of China. Although the relatively simple mass balance scheme ensures a good performance of runoff simulation during flood events, the model still has some defects. Previous studies have confirmed the importance of evapotranspiration (ET) and soil moisture content (SMC) in runoff simulation. In order to add more constraints to the original XAJ model, an energy balance scheme suitable for the XAJ model was developed and coupled with the original mass balance scheme of the XAJ model. The detailed parameterizations of the improved model, XAJ-EB, are presented in the first part of this paper. XAJ-EB employs various meteorological forcing and remote sensing data as input, simulating ET and runoff yield using a more physically based mass–energy balance scheme. In particular, the energy balance is solved by determining the representative equilibrium temperature (RET), which is comparable to land surface temperature (LST). The XAJ-EB was evaluated in the Lushui catchment situated in the middle reach of the Yangtze River basin for the period between 2004 and 2007. Validation using ground-measured runoff data proves that the XAJ-EB is capable of reproducing runoff comparable to the original XAJ model. Additionally, RET simulated by XAJ-EB agreed well with moderate resolution imaging spectroradiometer (MODIS)-retrieved LST, which further confirms that the model is able to simulate the mass–energy balance since LST reflects the interactions among various processes. The validation results prove that the XAJ-EB model has superior performance compared with the XAJ model and also extends its applicability.
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Chiang, Shen. "Hydrological model comparison and refinement through uncertainty recognition and quantification." 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/144539.
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Decker, Mark Ryan. "IMPROVING THE HYDROLOGICAL CYCLE IN LAND SURFACE CLIMATE MODELS." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/195627.
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The hydrological components of land surface climate models have increased greatly in complexity over the past decade, from simple bucket models to multilayer models including separate and distinct soil water and ground water components. While the parameterizations included in these models have also increased in complexity, the fundamental ability of the numerical solution for the vertical movement of soil water in the Community Land Model (or other land surface models) to simply maintain the hydrostatic solution of the original partial differential equation has yet to be determined.Also, the ability of current generation reanalysis products to simulate near surface quantities as gauged by flux tower measurements has yet to be determined.This study demonstrates that the numerical solution as used in CLM3.5 cannot maintain the hydrostatic state. An alternate form of the equation, titled the Modified Richards equation is presented so that the numerical solution maintains steady statesolutions. Also, an improved and simple bottom boundary condition is derived that itself doesn't destroy hydrostatic initial conditions. The new solution is demonstrated to be as accurate as proven numerical solutions while being one to three orders more computationally efficient. The Modified Richards equation together with the new bottom boundary condition is shown to improve the ability of CLM to simulate soil water, water table depth, and near surface turbulent fluxes.Comparison with flux tower observations shows that ERA-Interim better simulates near surface temperature and wind speed than other current generation reanalysis products. Reanalysis products are able to reproduce the flux tower observations on monthly timescales, and the errors between the products and the measurements are primarily due to biases. However, at six hourly timescales the errors are not only larger but also caused primarily by a lack of correlation with the observations.
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Zabel, Florian. "Land-atmosphere coupling between a land surface hydrological model and a regional climate model." Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-151446.
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Parsons, J. S. "A simulation model for subsurface and overland flow down a hillside in the Crimple Beck, N. Yorkshire." Thesis, University of Leeds, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376984.
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Zhang, Xuesong. "Evaluating and developing parameter optimization and uncertainty analysis methods for a computationally intensive distributed hydrological model." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3091.
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Keskin, Fatih. "Hydrological Model Study In Yuvacik Dam Basin By Using Gis Analysis." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608191/index.pdf.
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In this study, semi-distributed hydrological model studies were carried out with the
Mike11 model in Yuvacik dam Basin. The basin with a drainage area of 257.8 km2 is
located in 12 km South East of Izmit city in Türkiye. The basin is divided into three sub-basins named as Kirazdere, Kazandere and Serindere where each sub-basin is represented by its own characteristics. The largest peaks of inflow were observed when the storm events occur due to both snowmelt and rain. Therefore, observed flows for the period of 2001-2006 were grouped as daily and hourly storm events according to the event types such as rainfall, snowmelt or mixed events. Rainfall- Runoff Model (NAM) module of the model was used for the simulation of daily snowmelt and rain on snow events and Unit Hydrograph Method (UHM) module was used for the simulation of hourly rainfall events. A new methodology is suggested for the determination of Curve Number (CN) of the sub-basins by using the fractional area and topographic index values combined with hourly model simulations. The resulting CN values were used in the UHM module v and the suggested CN approach has been validated with the classical SCS-CN approach with GIS analysis. As a result of the study, the parameters of each sub-basin are calibrated with hourly and daily model simulations. The resulting flows are compared with the observed flows where model efficiency is tested with visual and statistical evaluations. The modeling studies give promising results for the computation of runoff during different seasons of a year.
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Sokrut, Nikolay. "The Integrated Distributed Hydrological Model, ECOFLOW- a Tool for Catchment Management." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-237.
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Hunukumbura, J. M. P. B. "Distributed hydrological model transferability across basins with different physio-climatic characteristics." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/126504.
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Kyoto University (京都大学)0048
新制・課程博士
博士(工学)
甲第14933号
工博第3160号
新制||工||1474(附属図書館)
27371
UT51-2009-M847
京都大学大学院工学研究科都市環境工学専攻
(主査)教授 椎葉 充晴, 教授 寶 馨, 准教授 立川 康人
学位規則第4条第1項該当
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Rogers, C. "Further development of distributed hydrological models with reference to the Institute of Hydrology distributed model." Thesis, University of Bristol, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373726.
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NGUYEN, DUC HA. "A COUPLED HYDROLOGICAL－ GEOTECHNICAL FRAMEWORK FOR FORECASTING SHALLOW LANDSLIDE HAZARD." Kyoto University, 2019. http://hdl.handle.net/2433/245320.
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Ekenberg, Madeleine. "Using a lumped conceptual hydrological model for five different catchments in Sweden." Thesis, Stockholms universitet, Institutionen för naturgeografi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-132245.
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Hydrological models offer powerful tools for understanding and predicting. In this thesis we havereviewed the advantages and disadvantages of physically based distributed hydrological models andconceptually lumped hydrological models. Based on that review, we went into depth and developed aMATLAB code to test if a simple conceptual lumped hydrological model, namely GR2M, wouldperform satisfactory for five different catchments in different parts of Sweden. The model had ratherunsatisfactory results and underestimated runoff systematically throughout all the five catchments.Additions to the model structure, such as a buffer allowing an approximation for snowmelt delay, wereintroduced with varying degrees of success. Based on analytical exploration of the model theory, it canbe seen that the instability of the model is mainly caused by one of the two free parameters used inGR2M, namely the maximum soil storage capacity. The optimization method used showed lowsensitivity to changes in this parameter while the calculated soil storage had strong dependence on thisparameter. Based on these results, it is fair to say that a simple lumped model likely does not have theability to represent the full range of hydrological conditions found along the gradient of Sweden.
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Srivastava, Prashant K. "Soil moisture estimation from SMOS satellite and mesoscale model for hydrological applications." Thesis, University of Bristol, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.617590.
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Soil moisture is an integral part of the Earth's hydrological cycle. Therefore, accurate estimation of the Earth's changing soil moisture is required to achieve sustainable land and water management to augment Numerical Weather Prediction (NWP) and forecasting skill, and to develop improved flood and drought monitoring capability. Unfortunately, most of the locations in the world do not have accurate soil moisture information on a relevant spatial and temporal scale. However, after latest advances in remote sensing and mesoscale models, it is now possible to estimate soil moisture using passive microwave satellite imaging such as Soil Moisture and Ocean Salinity (SMOS) and/or mesoscale model like Weather Research and Forecasting (WRF)-NOAH Land Surface Model (LSM). L-band passive remote sensing and WRF-NOAH LSM are potentially very useful for soil moisture sensing due to its all-weather capabilities and in-depth physics oriented relationship between soil emissivity and soil moisture, applicable for a diverse land use/land cover. In commensurate with new era in soil moisture remote sensing, this thesis explores the potential of SMOS satellite and WRFNOAH LSM for soil moisture retrieval over the temperate maritime climate. Also, soil moisture deficit (SM I) is found to be an integral component for irrigation scheduling, drought and flood prediction. Hence, the main focus of this thesis is the evaluation of soil moisture datasets as a method to effectively determine the SMD. All major areas of the improvement aided by the SMOS and WRF NOAH LSM arc addressed. Several novel approaches and investigations dealing with the SMOS soil moisture retrieval using Microwave Polarisation Difference Index (M PDI) and Radiative Transfer Equations arc examined. Input data (soil roughness, land surface temperature and vegetation opacity) sensitivity of different retrieval configurations are evaluated using the various algorithms. Thus, the thesis includes ( I) initial evaluation of SMOS satellite and ECMWF downscaled soil moisture using WRF-NOAH LSM with special reference to sensitivity of growing and non growing seasons; (2) assessment of land parameter retrieval model and tau-omega rationale; (3) a modified soil moisture retrieval algorithm from SMOS brightness temperature; and (4) sensitivity and uncertainty analysis of mesoscale model based product for SMD prediction. Further through this study, SMOS soil moisture downscaling schemes using artificial intelligence techniques with MODIS LST have also been proposed to improve the spatial resolution at a catchment scale and finally, data fusion techniques for improving soil l moisture deficit are presented with the SMOS and WRF-NOAII LSM. The overall finding indicates that the SMOS and WRF-NOAH LSM using ECMWF have been proven not only to improve data quality and soil moisture deficit estimation, but also have a great potential in fostering the soil moisture research and applications. The studies presented in this thesis will enhance our understanding of the Earth's water cycle, will help improve ECMWF forecast, SMOS algorithm, NWP and will lead to better water resource management practices.
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DeChant, Caleb Matthew. "Quantifying the Impacts of Initial Condition and Model Uncertainty on Hydrological Forecasts." Thesis, Portland State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3628148.
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Forecasts of hydrological information are vital for many of society's functions. Availability of water is a requirement for any civilization, and this necessitates quantitative estimates of water for effective resource management. The research in this dissertation will focus on the forecasting of hydrological quantities, with emphasis on times of anomalously low water availability, commonly referred to as droughts. Of particular focus is the quantification of uncertainty in hydrological forecasts, and the factors that affect that uncertainty. With this focus, Bayesian methods, including ensemble data assimilation and multi-model combinations, are utilized to develop a probabilistic forecasting system. This system is applied to the upper Colorado River Basin for water supply and drought forecast analysis.
This dissertation examines further advancements related to the identification of drought intensity. Due to the reliance of drought forecasting on measures of the magnitude of a drought event, it is imperative that these measures be highly accurate. In order to quantify drought intensity, hydrologists typically use statistical indices, which place observed hydrological deficiencies within the context of historical climate. Although such indices are a convenient framework for understanding the intensity of a drought event, they have obstacles related to non-stationary climate, and non-uniformly distributed input variables. This dissertation discusses these shortcomings, demonstrates some errors that conventional indices may lead to, and then proposes a movement towards physically-based indices to overcome these issues.
A final advancement in this dissertation is an examination of the sensitivity of hydrological forecasts to initial conditions. Although this has been performed in many recent studies, the experiment here takes a more detailed approach. Rather than determining the lead time at which meteorological forcing becomes dominant with respect to initial conditions, this study quantifies the lead time at which the forecast becomes entirely insensitive to initial conditions, and estimating the rate at which the forecast loses sensitivity to initial conditions. A primary goal with this study is to examine the recovery of drought, which is related to the loss of sensitivity to below average initial moisture conditions over time. Through this analysis, it is found that forecasts are sensitive to initial conditions at greater lead times than previously thought, which has repercussions for development of forecast systems.
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Rua, João Carlos Pereira. "Establishment of a hydrological model in a subbasin of the Sabor river." Master's thesis, Instituto Politécnico de Bragança, Escola Superior Agrária, 2012. http://hdl.handle.net/10198/7888.
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Land cover changes have consequences on hydrological processes of a basin
through changes in evapotranspiration and surface and subsurface water
movements in the landscape. Concern in the Mediterranean region has grown
recently due to the prospects of a reduction in precipitation and the occurrence
of large periods of drought potentially affecting human communities and
biodiversity. This research consisted in the implementation of a hydrological
model in the Upper Sabor river catchment, Northeastern Portugal, to evaluate
the impacts of land cover change on hydrological processes, namely water
yield. This catchment was chosen to represent landscape composition and
configuration in a changing mountain area of the region where types and rates
of land use change are known in detail for the last 50 years. SWAT (Soil and
Water Assessment Tool) was the model chosen to address the research
question. The implementation of SWAT consisted in data gathering, preparation
and database development: elevation, land use/land cover, weather, soils and
land management practices. Model validation was done considering data on
streamflow between 1973 and 2008. Monthly average results have shown that
water yield in the watershed depended on proportions of land cover in the
landscape. From the scenarios tested through simulation, we can highlight that
replacing agriculture by shrublands increased evatpotranspiration and
decreased water yield. On the other hand, a considerable augment in water
yield was registered when pastures became the dominant land use class.
Scenarios with the largest occupations in agriculture or pastures, were the least
evapotranspirative. Responses from land cover classes varied over the year.Alterações do uso do solo produzem efeitos nos processos hidrológicos de uma bacia através de alterações na evapotranspiração e no fluxo de água superficial e subterrânea na paisagem. Na região mediterrânica têm aumentado as preocupações devido a previsões de redução da precipitação e à ocorrência de períodos de seca prolongados, potencialmente afectando as comunidades humanas e a biodiversidade. Este trabalho consistiu na implementação de um modelo hidrológico na parte superior da bacia do rio Sabor, no nordeste de Portugal, para avaliar os impactos de alterações do uso do solo em processos hidrológicos, nomeadamente no caudal produzido. Esta bacia foi escolhida por representar uma paisagem de montanha em mudança numa região onde os tipos e taxas de alteração do uso do solo são conhecidos em detalhe nos últimos 50 anos. O SWAT (Soil and Water Assessment Tool) foi o modelo seleccionado para responder aos propósitos do trabalho. A implementação do modelo SWAT consistiu na recolha, preparação e desenvolvimento de uma base de dados com informação topográfica, de ocupação e uso do solo, meteorológica, dos tipos de solo e das práticas de gestão. A validação do modelo baseou-se em dados de caudal entre 1973 e 2008. Os resultados, em médias mensais, mostraram que a água produzida na bacia depende da cobertura do solo. Dos cenários testados, pode-se salientar que a substituição de área agrícola por área de matos faz aumentar a evapotranspiração e diminuir o caudal. Por outro lado, foi registado um aumento considerável do caudal quando na área, as áreas de pastagens passaram a ser dominantes. Os cenários com maior área agrícola ou de pastagem, foram os que apresentaram menor evapotranspiração. As respostas das classes de uso do solo variam ao logo do ano.
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Sarates, Junior Adiel Seffrin. "Optimizing two-dimesional shallow water based flood hydrological model with stream architectures." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/118254.
Full textAbstract:
O presente trabalho tem como objetivo explorar as dificuldades bem como os benefícios da utilização de arquiteturas Streams para a simulação de eventos hidrológicos baseados nas equações de águas rasas. Pra tal, é criado embasamento sobre modelagem hidrológica e os algumas classes de modelos existentes, arquiteturas heterogêneas e mais especificamente do modelo bidimensional usado baseado nas equações de Saint-Venan. Com isso é construida a linha de tempo referente às otimizações aplicadas ao modelo inicialmente serial até sua versão otimizada para GPUs, exibindo cada passo tomado em forma de algoritmo para chegar ao objetivo. Com estas otimizações foi obtido um speedup de quatro vezes para pequenas áreas e de 10 vezes com uma resolução média para uma grande área com um alto nível de detalhamento, quando comparado com uma versão de 24 threads.This study aims to explore the difficulties and the benefits of using Streams architectures for the simulation of hydrological events based on shallow water equations. For this purpose, is created foundation on hydrological modeling and some classes of existing models, heterogeneous architectures, and more specifically the two-dimensional model based on the equations used Saint-Venan. A timeline is constructed relating the applied optimizations beginning from the first serial model optimized for a GPU version showing each step taken in the form of an algorithm to reach the best performance. With these optimizations a speedup about 4 times was obtained for small areas and 10 times with a middle level of detailing for a large area with a high level of detailing. These results were produced comparing the GPU performance with a CPU and 24 threads version.
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Khaki, Mehdi. "Integration Frameworks for Merging Satellite Remote Sensing Observations with Hydrological Model Outputs." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/70487.
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With a growing number of available datasets especially from satellite remote sensing, there is a great opportunity to improve our knowledge of hydrological processes by integrating them with hydrological models. In this regard, data assimilation technique can be used to constrain the dynamic of a model with available observations in order to improve its estimates. In this thesis, a comprehensive data assimilation framework containing multiple stages is proposed and tested over various areas.
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Pasetto, Damiano. "Reduced Order Models and Data Assimilation for Hydrological Applications." Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3423054.
Full textAbstract:
The present thesis work concerns the study of Monte Carlo (MC)-based data assimilation methods applied to the numerical simulation of complex hydrological models with stochastic parameters. The ensemble Kalman filter (EnKF) and the sequential importance resampling (SIR) are implemented in the CATHY model, a solver that couples the subsurface water flow in porous media with the surface water dynamics. A detailed comparison of the results given by the two filters in a synthetic test case highlights the main benefits and drawbacks associated to these techniques. A modification of the SIR update is suggested to improve the performance of the filter in case of small ensemble sizes and small variances of the measurement errors. With this modification, both filters are able to assimilate pressure head and streamflow measurements and correct model errors, such as biased initial and boundary conditions. SIR technique seems to be better suited for the simulations at hand as they do not make use of the Gaussian approximation inherent the EnKF method. Further research is needed, however, to assess the robustness of the particle filters methods in particular to ensure accuracy of the results even when relatively small ensemble sizes are employed. In the second part of the thesis the focus is shifted to reducing the computational burden associated with the construction of the MC realizations (which constitutes the core of the EnKF and SIR). With this goal, we analyze the computational saving associated to the use of reduced order models (RM) for the generation of the ensemble of solutions. The proper orthogonal decomposition (POD) is applied to the linear equations of the groundwater flow in saturated porous media with a randomly distributed recharge and random heterogeneous hydraulic conductivity. Several test cases are used to assess the errors on the ensemble statistics caused by the RM approximation. Particular attention is given to the efficient computation of the principal components that are needed to project the model equations in the reduced space. The greedy algorithm selects the snapshots in the set of the MC realizations in such a way that the final principal components are parameter independent. An innovative residual-based estimation of the error associated to the RM solution is used to assess the precision of the RM and to stop the iterations of the greedy algorithm. By way of numerical applications in synthetic and real scenarios, we demonstrate that this modified greedy algorithm determines the minimum number of principal components to use in the reduction and, thus, leads to important computational savings.Questo lavoro di tesi riguarda lo studio di tecniche di assimilazione di dati basate sul metodo di Monte Carlo (MC) per la simulazione numerica di modelli idrologici in presenza di parametri stocastici. I metodi ensemble Kalman filter (EnKF) e sequential importance resampling (SIR) sono implementati nel modello CATHY, un modello idrologico che accoppia il flusso d'acqua sotterraneo in mezzi porosi con la dinamica del flusso d’acqua superficiale. Il confronto dettagliato dei risultati ottenuti con i due filtri in un caso test sintetico evidenzia i principali vantaggi e inconvenienti associati a queste tecniche. Per migliorare le prestazioni del metodo SIR, in questa tesi è proposta una modifica del passo di update che risulta fondamentale nei casi in cui si usi un ensemble di dimensioni ridotte e la varianza associata all'errore di misura sia piccola. Grazie a questa modifica, entrambi i filtri sono in grado di assimilare misure di carico piezometrico e portata, riducendo la propagazione temporale di errori di modellizzazione dovuti, ad esempio, all'utilizzo di condizioni iniziali o al contorno distorte. La tecnica SIR sembra essere più adeguata dell'EnKF per l’applicazione ai casi test presentati. Si dimostra infatti che l'ipotesi di Gaussianità, che contraddistingue il metodo EnKF, non è soddisfatta in questi casi test, rendendo preferibili metodi più generali come il SIR. Ulteriori approfondimenti sono comunque necessari per stabilire l'affidabilità dei metodi di tipo particle filter, in particolare per garantire l'accuratezza del filtro SIR anche quando viene usato un numero relativamente piccolo di realizzazioni. Siccome il passo di previsione dei metodi SIR ed EnKF è basato sul metodo di MC, la seconda parte della tesi riguarda il problema di ridurre gli onerosi tempi di calcolo associati alla costruzione delle realizzazioni di MC. Con questo obbiettivo, si analizza il risparmio in tempo computazione ottenuto dall'uso di modelli di ordine ridotto (RM) per la generazione dell'ensemble delle soluzioni. La tecnica proper orthogonal decomposition (POD) è applicata alle equazioni lineari del flusso d’acqua sotterraneo in mezzi porosi saturi con ricarica stocastica e distribuita spazialmente, oppure con conducibilità idraulica stocastica e descritta per zone. Gli errori di approssimazione introdotti dal modello ridotto sul calcolo delle singole realizzazioni di MC e sulle corrispondenti statistiche sono analizzati in diversi casi test al variare della distribuzione probabilistica dei parametri stocastici. Particolare attenzione è dedicata alla procedura di calcolo delle principal components che sono necessarie per la proiezione delle equazioni del modello nello spazio ridotto. Il greedy algorithm seleziona gli snapshots tra le realizzazioni di MC considerate, facendo in modo che le principal components finali siano indipendenti dalla particolare realizzazione dei parametri stocastici. Infine, viene introdotta una stima innovativa della norma dell'errore associato alla soluzione del modello ridotto. Tale stima, basata sul calcolo del residuo, è di fondamentale importanza per stimare la precisione del RM e, quindi, inferire sul numero di principal components da usare nella riduzione. Le applicazioni numeriche effettuate su casi test sintetici e reali dimostrano che il greedy algorithm così modificato determina un numero minore di principal components rispetto al metodo tradizionale, pur mantenendo la medesima accuratezza.
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Fontenele, Sávio de Brito. "Trocas hídricas entre rio e aquífero em duas litologias distintas do semiárido brasileiro." reponame:Repositório Institucional da UFC, 2015. http://www.repositorio.ufc.br/handle/riufc/16874.
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FONTENELE, Sávio de Brito. Trocas hídricas entre rio e aquífero em duas litologias distintas do semiárido brasileiro. 2015. 159 f. Tese (doutorado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2015.Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-03-22T20:42:29Z No. of bitstreams: 1 2016_tese_sbfontenele.pdf: 7131994 bytes, checksum: 7eb4f8d19a29992c9373c00fc1f1989c (MD5)
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The interaction between surface water and groundwater is a dynamic process in time and space influenced by factors such as soil moisture, hydrodynamic properties, geomorphology, storage and runoff. The quantification and modeling of the processes related to this dynamic constitute prerequisites for the effective water resources management, given that this interaction affects water availability, especially in semi-arid regions. Before this problem, this study aimed to simulate hydrological processes flow transmission between river and groundwater in basins characterized by distinct lithologies, inserted in the Brazilian semiarid region by generating a semi distributed and flexible hydrological model. Two distinct basins of Ceará semiarid region were monitored and used for application of the model developed. A watershed located in sedimentary structure with large underground water reserves (São Jose watershed in the sedimentary basin of Araripe - South of Ceará) and the other one inserted into the crystalline environment and characterized by water scarcity (Patos-Cariús-Iguatu subbasin - Jaguaribe river stretch in the Central-South region of Ceará). The monitoring of these areas between 2010 and 2014 enabled the generation of data and the choice of 10 events from each watershed monitored to evaluate the dynamic river-aquifer. In the evaluation of the data obtained by the monitoring observed aquifer recharges when large volumes precipitates occur in short periods of time. The high temporal spacing difficult the generation of large flows and the rising water levels of the alluvial aquifer. The proposed model was developed considering the three main processes of river-aquifer interaction: full wave propagation, vertical infiltration and groundwater flow. The simulations of the events showed that conductance of the riverbed and effective porosity are the most sensitive parameters of the model. Variations of these parameters allowed the reduction of flood peaks and consequently increases in the aquifer hydraulic loads. However, the simulations showed an underestimation of the hydraulic loads of the aquifer. For the surface discharges were obtained low efficiency ratios (-16.73 to -3.43) for short-term events and small magnitude. Already for long term events and high magnitude, the Nash and Sutcliffe efficiency coefficient performed between 0 and 1 (0.35 to 0.49), indicating a good behavior of the models used. However, for these events the average absolute error between the measured and the simulated loads remained high. The model needs to be adjusted to better define the dynamics of the river-aquifer interaction. A greater number of simulations in both watersheds, with the available events could indicate better where adjustments must be made. The possibility of application of MIRAS model in different lithological means and different spatial scales of semi-arid regions was not possible due to the inability to simulate the model for MHSJ. Thus, one must understands the failure to formulate an alternative and possibly improve the model. Because the use of this tool is the best option for resolving problems and decision making.
A interação entre água superficial e subterrânea é um processo dinâmico no tempo e no espaço influenciado por fatores como umidade do solo, propriedades hidrodinâmicas, geomorfologia, armazenamento e escoamento superficial. A quantificação e a modelagem dos processos relacionados a essa dinâmica constituem-se pré-requisitos para a gestão eficiente de bacias hidrográficas, haja vista que essa interação afeta a disponibilidade hídrica, principalmente em regiões semiáridas. Diante dessa problemática, este estudo objetivou simular processos hidrológicos de transmissão de fluxo entre rio e aquífero em bacias hidrográficas caracterizadas por litologias distintas, inseridas na região semiárida brasileira, através da geração de um modelo hidrológico semidistribuído e flexível. Duas bacias hidrográficas distintas da região semiárida cearense foram monitoradas e utilizadas para aplicação do modelo desenvolvido. Uma microbacia localizada em meio sedimentar com grandes reservas hídricas subterrâneas (microbacia hidrográfica do São José na bacia sedimentar do Araripe – Sul do Ceará) e a outra inserida no meio cristalino e caracterizada por escassez hídrica (bacia hidrográfica Patos-Cariús-Iguatu – trecho do rio Jaguaribe na região Centro-Sul do Ceará). O monitoramento dessas áreas entre 2010 e 2014 possibilitou a geração de dados e a escolha de 10 eventos de cada bacia monitorada para avaliação da dinâmica rio-aquífero. Na avaliação dos dados obtidos pelo monitoramento observou-se recargas aquíferas quando grandes volumes precipitados ocorrem em curtos espaços de tempo. O elevado espaçamento temporal dificultaram a geração de grandes vazões e a elevação dos níveis freáticos do aquífero aluvionar. O modelo proposto foi elaborado considerando os três principais processos da interação rio-aquífero: propagação de onda de cheia, infiltração vertical e fluxo subterrâneo. As simulações dos eventos mostraram que condutância do leito do rio e porosidade efetiva são os parâmetros mais sensíveis do modelo. Variações desses parâmetros possibilitaram a redução dos picos de cheia e consequentemente acréscimos nas cargas hidráulicas aquíferas. No entanto, as simulações realizadas apresentaram subestimativas das cargas hidráulicas do aquífero. Para as descargas superficiais obteve-se baixos coeficientes de eficiência (-16,73 a -3,43) para eventos de curta duração e pequena magnitude. Já para eventos de longa duração e elevada magnitude, o coeficiente de eficiência de Nash e Sutcliffe apresentou-se entre 0 e 1 (0,35 a 0,49), indicando um bom comportamento dos modelos utilizados. No entanto, para esses eventos o erro médio absoluto entre as cargas medidas e as simuladas continuaram elevados. O modelo precisa de ajustes para definir melhor a dinâmica da interação rio-aquífero. Um número maior de simulações nas duas bacias hidrográficas, com os eventos disponíveis poderia indicar melhor onde devem ser feitos os ajustes. A possibilidade de aplicação do modelo MIRAS em diferentes meios litológicos e escalas espaciais distintas de regiões semiáridas não fora possível devido à impossibilidade de simular o modelo para a MHSJ. Dessa forma, precisa-se entender as falhas para formular uma alternativa e, possivelmente, melhorar o modelo. Pois, o uso dessa ferramenta é a melhor opção para a resolução de problemas e tomada de decisão.
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Sachse, Agnes Christiane Felicia. "Hydrological and hydro-geological model of the Western Dead Sea catchment, Israel and West Bank." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-222296.
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Groundwater is the only fresh water resource in the semi-arid to hyper-arid Western Dead Sea catchment. Due to exploitation of groundwater the water level is decreasing in the surrounding Cretaceous aquifer system and sustainable water management is needed in order to prevent the progressive yields and contamination of those water resources. In addition, the water level of the Dead Sea decreases dramatically by at least one meter per year. This is connected to channel off the water from the Jordan River to supply intensive agriculture in the semi-arid to hyper-arid region.
Hydrological and hydro-geological analysis and modelling in arid regions, like the study area, frequently suffer from data scarcity and uncertainties regarding rainfall and discharge measurements. The study showed that spatial and temporal interpolations as well as additional methods (e.g. empirical relationships and simultaneous numerical approaches) were suitable tools to overcome data shortage for modelling.
Water balances are the result of a calibrated model and are the basis for sustainable management of surface and subsurface water resources. The present study investigates beside the hydrological characterisation of selected sub-catchments (wadis) also the hydro-geology of the Judean limestone aquifer and calculates a comprehensive water balance of the entire western flank of the Dead Sea by the application of two numerical open source codes: OpenGeoSys (OGS) and J2000g.
The calibrated two-dimensional hydrological model J2000g provides a 33 years time series of temporal and spatial distributed groundwater recharge for the numerical groundwater flow model of OGS. The mean annual groundwater recharge of 139.9 · 10^6 m^3ˑ a^-1 is nearly completely depleted by abstractions from pumping wells close to the replenishment area in the Judea Mountains.
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Garcia, Luis Jimenez, Guzman Osnar Iruri, and Sissi Santos Hurtado. "Hazard map based on the simulation of sludge flow in a two-dimensional model, Case Quebrada Malanche-Punta Hermosa -Lima-Perú." Institute of Electrical and Electronics Engineers Inc, 2020. http://hdl.handle.net/10757/656417.
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El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.This research presents the numerical simulation to reproduce the transport and deposition processes of the sludge flow on March 15, 2017, strongly impacting the town of Pampapacta in Punta Hermosa-Peru.The debris flow initiation process in the basin was represented by hydrographs obtained from the estimated volumes of stormwater runoff and solid materials. The sludge flow was modeled in Flo2D to calculate hazard maps with the discharge event and others with different return periods.The numerical simulation results show acceptable results in relation to what happened. The model used to assess the hazard due to debris flow can predict and delineate, with acceptable precision, potentially hazardous areas for a landslide. The application of the proposed methodology to assess the hazard of disasters due to debris flows in basins and streams is useful to understand the extent of the impact of the mud flow during extreme weather events, as well as to develop emergency plans and formulate disaster policies.
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Abdelnour, Alex Gabriel. "Assessing ecosystem response to natural and anthropogenic disturbances using an eco-hydrological model." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42899.
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The impact of natural and anthropogenic disturbances on catchment hydrological and biogeochemical dynamics are difficult or impossible to capture through experimentation or observation alone. Process-based simulation models can address this need by providing a framework for synthesizing data describing catchment responses to climate, harvest, fire, and other disturbances. However, existing models are either too simple to capture important process-level hydrological and biogeochemical controls on ecosystem responses to disturbance, or are too computationally expensive to simulate the local dynamics over large watershed areas, or require a high level of expertise to implement.
To this end, a spatially distributed, physically based, eco-hydrological model (VELMA: Visualizing Ecosystems for Land Management Assessments) that is both computationally efficient and relatively easy to implement is developed. VELMA is a state-of-the-art model with real-time visualization tools that shows temporal and spatial patterns of state and flux variables, and is used to address the effects of changes in climate, land-use, and other interacting stressors on multiple ecosystem services such as timber production, carbon sequestration, regulation of water quality and quantity and reduction of greenhouse gases at scales relevant to formulating management decisions.
In this study, VELMA was applied to the H.J. Andrews Experimental forest, an intensively studied watershed with observed daily temperature, precipitation, streamflow, and nutrient losses data. VELMA was first used to explore the factors that controls catchment response to forest harvest. Specifically, elucidate how forest harvest factors such as harvest location and amount control watershed hydrological and biogeochemical fluxes. Thereafter, VELMA was used to reconstruct and analyze the impact of two significant disturbance events − a stand replacing fire and a 100% clearcut − on vegetation and soil carbon and nitrogen dynamics. Finally, VELMA was used to explore the potential impact of climate change on catchment hydrological regime, site productivity and carbon and nitrogen dynamics at high spatial resolution relevant to formulating management decision.
The main insights from this study include: (1) streamflow, nutrient losses to the stream, and gaseous carbon and nitrogen losses to the atmosphere are strongly sensitive to the location of harvest as a result of the spatial variation in soil water content, plant nitrogen uptake, soil organic carbon decomposition, nitrification, and denitrification within the watershed, (2) forested riparian buffers reduce water and nutrient losses to the stream through plant transpiration, plant nitrogen uptake, soil storage, and soil microbial decomposition, (3) following fire and harvest, losses of N from the terrestrial system to the stream are tightly constrained by the hydrological cycle and driven mainly by wet-season rain events large enough to generate hydrologic connectivity and flushing of nutrients along hillslopes, (4) climate change strongly impacts the hydrological regime in the Pacific Northwest as a result of less snowpack, earlier snowmelt, higher winter streamflow, lower summer streamflow, and soil moisture deficit, and (5) climate change increases plant and soil biomass accumulation as a result of longer growing season and higher soil organic decomposition, reduce water quality by increasing the amount of nutrients that reach the stream, and transforms the ecosystem into a net source of carbon to the atmosphere.
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Hall, Graham. "An Integrated Meteorological /Hydrological Model for the Mawddach Catchment, North Wales Volume 1." Thesis, Bangor University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491689.
Full textAbstract:
This project makes a study of meteorological and hydrological processes operating in the Mawddach river catchment ofNorth Wales, with the objectives of recommending catchment management options to reduce the severity of flooding and to produce a design for a high resolution flood forecasting model for the catchment. An array of rain gauges installed across the catchment has allowed the detailed mapping of rainfall distributions. Two patterns are identified, with axes of high rainfall running NW-SE and N-S respectively. Within these zones, the locations of rainfall maxima do not necessarily correspond with the highest altitude. The approach direction of weather systems and the funnelling ofair flows along deep valleys appear to control rainfall distribution. A series of flood events are examined, particularly the convective squall line storm of3 July 2001 and the period ofintense frontal rainfall of3-4 February 2004. Modelling of rainfall is carried out using the MM5 meteorological model. It is found that frontal rainfall can be forecast to a high degree of accuracy. Convective thunderstorm events are less predictable, and different convective physics schemes within the MM5 package had differing degrees of success in forecasting the July 2001 Mawddach storm. The catchment is an area of hard, low permeability Palaeozoic rocks. Thick deposits of glacial and periglacial materials are locally present, particularly in valleys. Experiments to monitor hillslope throughflow and runoff show that these superficial deposits playa crucial role in controlling the antecedent conditions necessary for saturation-excess flood events. Deep blanket peat is found at a number of upland sites in the catchment. Watertable monitoring indicates that older peat has a low water storage capacity, with saturation possible within a few hours of heavy rainfall. Areas ofyoung Sphagnum peat can act as regulating reservoirs for flood water, and should be conserved. Field monitoring ofriver bed temperatures shows that resurgence of groundwater can occur in the deep river valleys of Coed y Brenin during storm events. However, resurgence occurs after the flood peak has passed and is not thought to influence the severity of flooding. Flood scenarios for the town ofDolgellau are investigated, including the effects of continued gravel deposition in the River Wnion. Gravel supply should be controlled through planting of native broadleaf woodland on riverbanks of(peri)glacial materials. A flood reduction scheme is proposed, with establishment of wet woodland and creation ofa flood interception basin in the lower Wnion valley. Field monitoring ofriver and tidal flows at the head of the Mawddach estuary indicates no additive effect ofriver flood and tidal peaks. Flooding at the head of the estuary is generally caused by river flows. Further reclamation of salt marsh could worsen upstream flooding. A new hillslope model has been written which allows for changing antecedent soil moisture conditions. The model generates a soil distribution based on the HOST (hydrology of soil types) scheme. A flood forecasting system is developed by combining the hillslope model with MM5 and existing river routing and floodplain modelling components. The system operates by a combination of parallel and distributed processing, to produce forecasts within an operationally useful timescale.
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Bastawesy, Mohammed El. "Development of GIS based hydrological model for hyper-arid catchment of Wadi Haymour." Thesis, University of Reading, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430837.
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Zhang, Fangli. "A particle-set distributed hydrological model for the dynamic simulation of surface runoff." HKBU Institutional Repository, 2017. https://repository.hkbu.edu.hk/etd_oa/472.
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1.1\xThis study proposed a particle-set distributed hydrological model for the dynamic simulation of rainfall-runoff process. With the supports of remote sensing, GIS, terrain analysis and distributed computing techniques, a representation-simplified and physically-based high-performance watershed framework has been developed. It simplifies the underlying watershed with a flow path network model, and represents the moving surface flow with independent runoff particles.;1.2\xThe original idea was to investigate a real-time modeling system for the space-time dynamics of increasingly frequent extreme rainfall events. Short-term heavy rains may cause further damages by spawning floods and landslides. It is quite essential to understand how the rainfall water moves across the watershed surface as early as possible. A modelling system with high-performance in simulation efficiency and space-time prediction accuracy would be very desirable.;1.3\xWatershed modeling is the primary way to explore the hydrological cycle at a local scale. Existing models are classified as empirical lumped, conceptual semi-distributed and physically-based distributed models. The first two types of models have focused more on predicting outlet discharges rather than estimating spatiotemporal flow dynamics. The application of physically-based models has always been hampered by some common shortcomings like over-parameterization, inflexibility and computational burden. With the increasing support from terrain analysis and parallel computing techniques, a number of previous studies have made some efforts to improve the performance in dynamic and real-time simulation. However, research gaps still exist in realistic representation, physical description and real-time simulation.;1.4\xThis study, therefore, developed the particle-set modeling system on the basis of flow path network model. This one-dimensional topological structure was created beforehand to represent the three-dimensional watershed, and a series of particle beams were dynamically generated to simulate the surface flow. Under the control of flow velocities, these runoff particles would keep on moving along with the flow paths, which can represent the spatial distributions of surface water in time.;1.5\xTo validate the proposed particle-set framework, a prototype of particle-set system was implemented by programming methods with the assistance of third-party platforms. Three experiments were undertaken to respectively evaluate the performance in prediction accuracy, simulation efficiency and parameter sensitivity. More specifically, a total of 10 rainfall events and up to 128 computer processors were tested. In addition, the influences of underlying spatial scale and source sampling density on hydrological responses were explored with comparative tests.;1.6\xThe accuracy validation comes in two parts, the representation loss in terrain analysis, and the discharge error in hydrological modeling. The experimental results indicate that the TIN-based flow path network has maintained the terrain features at a very high level with much less data storage, and the particle-set framework has achieved quite acceptable predictions of outlet discharges. Besides, the efficiency evaluation concerns with two aspects, parallel portion and parallel efficiency. The speed-up results indicate that about 99% of the computational workloads can be computed in parallel, and the particle-based scheme can achieve almost the ideal parallel efficiency. In addition, the sensitivity test focuses also on two parameters, underlying spatial scale and source sampling density. The preliminary results show that the particle-set model has shown a good reliability and stability as scale gets coarser or density becomes sparser.;1.7\xThis study will contribute to the understanding of short-term rainfall-runoff events at a basin scale. The particle-set distributed hydrological model has been proven to provide real-time spatio-temporal dynamics of surface flow. Further studies would still be required to apply it to real world scenarios.;1.8\xKeywords: terrain analysis, watershed hydrology, rainfall-runoff process, flow path network, particle system, parallel computing
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Wu, Qiusheng. "Hydrological and Ecological Analysis of Topographic Structure and Wetland Landscape." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1439307917.
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Tondu, Yohann. "Simulation of the Paris 1910 flood with a lumped hydrological model: the influence of frozen soil." Thesis, KTH, Vattendragsteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-96310.
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In 1910, Paris experienced its biggest flood in the 20th century. In 2010, for the anniversary of this event – supposed to happen every 100 years ! – the flood prediction model that is now used on the Seine basin was tested on its simulation,… and failed to reproduce the observed flood volume. This paper will try to explain, and correct, such disappointing results. Many hypotheses have been tested and based on their results, it has been decided to develop a frost module in order to assess the influence of this phenomenon – that is not taken into account by the lumped hydrological model that is used – on the flood formation. A soil temperature model using air temperature as input data was also designed because soil temperature data were not available in 1910. The addition of the frost module did not, however, bring many improvements to the 1910 flood simulation because frost is a too rare phenomenon on the Seine basin for the module to be correctly calibrated. However, new perspectives are presented to continue the research on this phenomenon.
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Raina, Rajeev. "Development of a cell-based stream flow routing model." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/2219.
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This study presents the development of a cell-based routing model. The model developed is a two parameter hydrological routing model that uses a coarse resolution stream network to route runoff from each cell in the watershed to the outlet. The watershed is divided into a number of equal cells, which are approximated as cascade of linear reservoirs or tanks. Water is routed from a cell downstream, depending on the flow direction of the cell, using the cascade of tanks. The routing model consists of two phases, first is the overland flow routing, which is followed by the channel flow routing. In this study, the cell-to-cell stream flow routing model is applied to the Brazos River Basin to demonstrate the impact of the cascade of tanks on the flow over a simple linear reservoir method. This watershed was tested with a uniform runoff depth in absence of observed runoff data. A case study on Waller Creek in Austin, Texas with observed runoff depths and stream flow is used to demonstrate the calibration and validation of model parameters.
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Comarova, Zoia A. Ms. "Assessment of Watershed Model Simplification and Potential Application in Small Ungaged Watersheds: A Case Study of Big Creek, Atlanta, GA." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/geosciences_theses/36.
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Technological and methodological advances of the past few decades have provided hydrologists with advanced and increasingly complex hydrological models. These models improve our ability to simulate hydrological systems, but they also require a lot of detailed input data and, therefore, have a limited applicability in locations with poor data availability. From a case study of Big Creek watershed, a 186.4 km2 urbanizing watershed in Atlanta, GA, for which continuous flow data are available since 1960, this project investigates the relationship between model complexity, data availability and predictive performance in order to provide reliability factors for the use of reduced complexity models in areas with limited data availability, such as small ungaged watersheds in similar environments. My hope is to identify ways to increase model efficiency without sacrificing significant model reliability that will be transferable to ungaged watersheds.