Author: Jeffrey Hieronymus
Publisher:
ISBN:
Category : Estuarine ecology
Languages : en
Pages : 148
Book Description
Calibration and Verification of a Two-dimensional Laterally Averaged Mechanistic Model of the Neuse River Estuary
Author: Jeffrey Hieronymus
Publisher:
ISBN:
Category : Estuarine ecology
Languages : en
Pages : 148
Book Description
Publisher:
ISBN:
Category : Estuarine ecology
Languages : en
Pages : 148
Book Description
Selected Papers from the 15th Estuarine and Coastal Modeling Conference
Author: Richard P. Signell
Publisher: MDPI
ISBN: 3039212699
Category : Science
Languages : en
Pages : 434
Book Description
This book is a printed edition of the Special Issue Selected Papers from the 15th Estuarine and Coastal Modeling Conference that was published in JMSE
Publisher: MDPI
ISBN: 3039212699
Category : Science
Languages : en
Pages : 434
Book Description
This book is a printed edition of the Special Issue Selected Papers from the 15th Estuarine and Coastal Modeling Conference that was published in JMSE
Calibration and Verification of a Two-dimensional Depth Averaged Hydrodynamic Model for Modeling Flow Around Bendway Weirs in a Mild Gradient Sand Bed River
Author: Brian Gregory Wardman
Publisher:
ISBN:
Category : Groins (Shore protection)
Languages : en
Pages : 160
Book Description
Publisher:
ISBN:
Category : Groins (Shore protection)
Languages : en
Pages : 160
Book Description
Neuse River Estuary Modeling and Monitoring Project Stage 1
Author: James D. Bowen
Publisher:
ISBN:
Category : Algal blooms
Languages : en
Pages : 124
Book Description
Publisher:
ISBN:
Category : Algal blooms
Languages : en
Pages : 124
Book Description
Development of a Laterally Averaged Two-dimensional Model for a Tidal Channel
Author: Sergio Eiger
Publisher:
ISBN:
Category : Estuaries
Languages : en
Pages : 132
Book Description
Publisher:
ISBN:
Category : Estuaries
Languages : en
Pages : 132
Book Description
Use of a Two-dimensional Flow Model to Quantify Aquatic Habitat
Author: D. Michael Gee
Publisher:
ISBN:
Category : Aquatic biology
Languages : en
Pages : 22
Book Description
This paper describes the impacts of potential hydropower retrofits on downstream flow distributions at Lock and Dam No. 8 on the upper Mississippi River. The model used solves the complete Reynolds equations for two-dimensional free-surface flow in the horizontal plane using a finite element solution scheme. RMA-2 has been in continuing use and development at the Hydrologic Engineering Center and elsewhere for the past decade. Although designed primarily for the simulation of hydraulic conditions, RMA-2 may be used in conjunction with related numerical models to simulate sediment transport and water quality. In this study, velocity distributions were evaluated with regard to environmental, navigational and small-boat safety considerations. Aquatic habitat was defined by depth, substrate type and current velocity. Habitat types were quantified by measuring the areas between calculated contours of velocity magnitude (isotachs) for existing and project conditions. The capability for computing and displaying isotachs for the depth-average velocity, velocity one foot from the bottom and near the water surface was developed for this study. The product of this study effort is an application of the RMA-2 model that allows prediction of structural aquatic habitat in hydraulicaly complex locations. Elements of the instream flow group methodology could be incorporated to provide detailed predictions of impacts to habitat quality. Calibration of the numerical model to field measurements of velocity magnitude and direction is also described.
Publisher:
ISBN:
Category : Aquatic biology
Languages : en
Pages : 22
Book Description
This paper describes the impacts of potential hydropower retrofits on downstream flow distributions at Lock and Dam No. 8 on the upper Mississippi River. The model used solves the complete Reynolds equations for two-dimensional free-surface flow in the horizontal plane using a finite element solution scheme. RMA-2 has been in continuing use and development at the Hydrologic Engineering Center and elsewhere for the past decade. Although designed primarily for the simulation of hydraulic conditions, RMA-2 may be used in conjunction with related numerical models to simulate sediment transport and water quality. In this study, velocity distributions were evaluated with regard to environmental, navigational and small-boat safety considerations. Aquatic habitat was defined by depth, substrate type and current velocity. Habitat types were quantified by measuring the areas between calculated contours of velocity magnitude (isotachs) for existing and project conditions. The capability for computing and displaying isotachs for the depth-average velocity, velocity one foot from the bottom and near the water surface was developed for this study. The product of this study effort is an application of the RMA-2 model that allows prediction of structural aquatic habitat in hydraulicaly complex locations. Elements of the instream flow group methodology could be incorporated to provide detailed predictions of impacts to habitat quality. Calibration of the numerical model to field measurements of velocity magnitude and direction is also described.
Ce-Qual W2
The Effect of Grid Scale on the Calibration of Two-dimension River Models Through the Drag Coefficient
Author: Rachel Elizabeth Chisolm
Publisher:
ISBN:
Category :
Languages : en
Pages : 170
Book Description
New survey technologies are able to provide detailed data on the form and topography of riverbeds. With this increased data resolution, the required computational time rather than data availability has become the limiting factor for river models. Detailed bathymetric data can be used to provide better empirical representation of drag and roughness at fine scales, allowing a priori selection of roughness using known physics rather than a posteriori calibration. However, we do not have sufficient guidance or understanding from the literature to represent known heterogeneities smaller than our practical grid scale. The problem is what to do with known subgrid-scale bathymetric features and roughness when our models must use a coarser computational grid. In this project, we simplify this complex problem to analyzing flow in a simple open channel with a single patch of relatively high roughness against an otherwise uniform background of low roughness. We model this open channel with a two-dimensional, depth-averaged river model. By running multiple simulations using different grid sizes we gain insight into how the relationship between the grid cell size and the patch size affects the appropriate physical selection of roughness parameter. As the primary focus, the present work proposes and investigates several methods for upscaling known fine-scale drag coefficient data to a coarser grid resolution for a model. For the tested conditions, it appears that a simple area-weighted linear average is simple to apply and creates a flow field very similar to the best results achieved by calibration. As a secondary issue, the present work examines grid-dependent behaviors when using model calibration. Although recalibration of models for different grid scales is a common practice among modelers, we could find relatively little documentation or analysis. In our work, we examine both single-cell calibration (i.e. changing roughness in only the cell containing the rough patch) and multiple-grid cell calibration involving neighbor cells. With either method, improving calibration required multiple model simulations and comparative analysis for each tested grid size and was inefficient compared to the upscaling approach. As expected, the calibration at a given grid size was always inappropriate for a different grid size.
Publisher:
ISBN:
Category :
Languages : en
Pages : 170
Book Description
New survey technologies are able to provide detailed data on the form and topography of riverbeds. With this increased data resolution, the required computational time rather than data availability has become the limiting factor for river models. Detailed bathymetric data can be used to provide better empirical representation of drag and roughness at fine scales, allowing a priori selection of roughness using known physics rather than a posteriori calibration. However, we do not have sufficient guidance or understanding from the literature to represent known heterogeneities smaller than our practical grid scale. The problem is what to do with known subgrid-scale bathymetric features and roughness when our models must use a coarser computational grid. In this project, we simplify this complex problem to analyzing flow in a simple open channel with a single patch of relatively high roughness against an otherwise uniform background of low roughness. We model this open channel with a two-dimensional, depth-averaged river model. By running multiple simulations using different grid sizes we gain insight into how the relationship between the grid cell size and the patch size affects the appropriate physical selection of roughness parameter. As the primary focus, the present work proposes and investigates several methods for upscaling known fine-scale drag coefficient data to a coarser grid resolution for a model. For the tested conditions, it appears that a simple area-weighted linear average is simple to apply and creates a flow field very similar to the best results achieved by calibration. As a secondary issue, the present work examines grid-dependent behaviors when using model calibration. Although recalibration of models for different grid scales is a common practice among modelers, we could find relatively little documentation or analysis. In our work, we examine both single-cell calibration (i.e. changing roughness in only the cell containing the rough patch) and multiple-grid cell calibration involving neighbor cells. With either method, improving calibration required multiple model simulations and comparative analysis for each tested grid size and was inefficient compared to the upscaling approach. As expected, the calibration at a given grid size was always inappropriate for a different grid size.
Mathematical Modeling and Parameter Identification in a Two-dimensional Estuary
Author: Wen-sen Chu
Publisher:
ISBN:
Category : Estuaries
Languages : en
Pages : 48
Book Description
Publisher:
ISBN:
Category : Estuaries
Languages : en
Pages : 48
Book Description
Application of a Two-dimensional Model of Hydrodynamics and Water Quality (CE-QUAL-W2) to DeGray Lake, Arkansas
Author: James L. Martin
Publisher:
ISBN:
Category : CE-QUAL-W2 (Computer program)
Languages : en
Pages : 86
Book Description
Publisher:
ISBN:
Category : CE-QUAL-W2 (Computer program)
Languages : en
Pages : 86
Book Description