#352 - Advanced 1D/2D Modeling with HEC-RAS (FY22)

Date: 4-8 April 2022

Objectives

This is an advanced course in applying computer program HEC-RAS. The course provides participants with the knowledge to effectively use computer program HEC-RAS to analyze difficult hydraulic conditions in natural and constructed channels, utilizing one-dimensional and two-dimensional modeling techniques.

Topics include: Developing terrain models for 2D modeling; developing Manning’s n layers; creating and modifying a 2D computational mesh; boundary conditions for 2D Flow Areas; hooking up 1D elements to 2D Flow Areas; running a combined 1D/2D model; viewing 1D/2D results with RAS Mapper; hydraulic structures inside of 2D areas; and detailed channel and floodplain modeling with 2D flow areas. Special topics for dam and levee breaching, and using 2D modeling for hydraulic structures, will also be included.

PDF material for the course Agenda, presentations, and workshops are provided below.

Agenda

Monday

Time		Topic	Objective	Material
0800-0900	L0	Introductions and pre-course activities	Welcome and discussion of class expectations	Agenda
0900-0930	L1.1	Example HEC-RAS Modeling	Overview of HEC-RAS capabilities using example applications for 2D modeling Introduction to the validation and verification of HEC-RAS.	L 1.1-Overview of HEC-RAS Modeling Capabilities.pdf
0930-1000	D1.2	HEC-RAS Demonstration	Demonstration of using HEC-RAS to create a 2D model (Steps to create a RAS Model)
1000-1015		Break
1015-1100	L1.3	Subgrid Bathymetry	Discussion on the use of sub-grid bathymetry for finite volume computations in HEC-RAS. The benefits of variable cell size on computational performance will be discussed.	1.3 HEC-RAS Subgrid Bathymetry.pdf
1100-1130	L1.4	Introduction to the 2D Equations	This presentation discusses the underlying 2D hydraulic equations used in HEC-RAS.	1.4 Intro to 2D Equations.pdf
1130-1230		Lunch
1230-1315	L1.5	Creating an HEC-RAS Terrain	Developing a terrain model and creating dataset for 2D modeling	1.5 Creating a RAS Terrain.pdf
1315-1415	W1.6	Creating an HEC-RAS Terrain Workshop	Hands- on work creating an HEC-RAS Terrain dataset	1.6 Workshop - Creating a RAS Terrain.pdf
1415-1430		Break
1430-1515	L1.7	Mesh Generation and Refinement	This presentation will discuss the basic concepts of creating a 2D Mesh in HEC-RAS and then how to improve and refine a 2D Mesh with Breaklines and Refinement Regions.	1.7 Mesh Generation and Refinement.pdf
1515-1545	D1.8	Vector Editing in RAS Mapper	Demonstration of using editing tools in RAS Mapper to create a mesh: polygons, breaklines, and refinement regions.	1.8 Intro RAS Mapper Editing.pdf
1545-1700	W1.9	Mesh Generation and Refinement Workshop	This workshop will provide hands-on experience in using HEC-RAS Mapper to create a 2D flow area mesh and refine it to capture high ground using breaklines and refinement regions	1.9 Workshop - 2D Mesh Generation.pdf

Tuesday

Time		Topic	Objective	Material
0800-0845	L2.1	Boundary and Initial Conditions	The different types of boundary conditions and establishing initial conditions will be discussed.	2.1 Boundary and Initial Conditions.pdf
0845-0915	L2.2	Running a 2D Model	Discussion of essential parameters and computational options for running a 2D model including equation choice, cell size considerations, and time step considerations.	2.2 Running a 2D Model.pdf
0915-0930		Break
0930-1100	W2.3	Creating a Simple 2D Model Workshop	Students will create their first 2D model. Refinement of the model will be performed to understand the effect of model parameters.	2.3 Workshop - Creating a 2D Model.pdf
1100-1130		Review		2.3 WSolution - Creating a 2D Model.pdf
1130-1230		Lunch
1230-1315	L2.4	Visualization of HEC-RAS Results in HEC-RAS Mapper	An introduction to RAS Mapper is provided, specifically for visualizing HEC-RAS results.	2.4 RAS Mapper Visualization.pdf
1315-1345	D2.5	HEC-RAS Mapper Demonstration
1345-1400		Break
1400-1430	L2.6	Land Classification Data	This discussion will cover creating an Land Classification dataset for use with Manning's n values in RAS Mapper.	2.6 Land Classification and Mannings n Values.pdf
1430-1515	W2.7	Land Classification Data	Student will learn how to bring land cover data into a Land Classification dataset and associated Manning's n values.	2.7 Workshop - Land Cover Mannings n.pdf
1515-1545		Review
1545-1600	L2.8	Equation Selection	A discussion on the use of Diffusion Wave and Full Shallow Water Equations in HEC-RAS is presented. A discussion of scenarios where the equations are appropriate is also provided.	2.8 Equation Selection - DWvSWE.pdf
1600-1630	L2.9	Advanced Computation Options	Discussion of more advanced parameters and computational options for running a 2D model including equation choices, turbulence, and matrix solvers.	2.9 Advanced Computation Options.pdf
1630-1700	L2.10	1D vs 2D Modeling	This presentation discusses 1D vs 2D modeling and how to choose the appropriate modeling method.	2.10 1D vs 2D Modeling.pdf

Wednesday

Time		Topic	Objective	Material
0800-0830	L3.1	Combined 1D/2D Modeling	Discussion of modeling channels with 1D rivers reaches/cross sections combined with floodplains/levees using 2D Flow Areas	3.1 Combined 1D River and 2D Floodplain-LeveeAreas.pdf
0830-0930	W3.2	Combined 1D/2D Modeling Workshop	Use a combined 1D/2D model to evaluate a protected area using 2D Flow Area and a Lateral Structure to define a levee. Levee overtopping and breaching will also be analyzed.	3.2 Workshop - Combined 1D2D Modeling.pdf
0930-1000		Review		3.2 WSolution - Combined 1D2D Modeling.pdf
1000-1015		Break
1015-1045	L3.3	Dam Breach with 2D Flow Area	Discussion of how to use 2D Flow Areas with 1D reaches and storage areas to perform a dam breach analysis. Discussion on using the SA/2D Connection for modeling a dam, outlets, and the dam breach.	3.3 Dam Break Modeling 2D.pdf
1045-1115	L3.4	Determination of Dam Breach Parameters	This presentation will discuss estimating dam breach parameters for modeling dam breach scenarios.	3.4 Determination of Dam Breach Parameters.pdf
1115-1215		Lunch
1215-1345	W3.5	Dam Breach with 2D Flow Areas Workshop	Students will create an HEC-RAS model to utilize the breach functionality and evaluate parameters.	3.5 Workshop - Dam Breach Analysis.pdf
1345-1415		Review		3.5 WSolution - Dam Breach Analysis.pdf
1415-1430		Break
1430-1500	L3.6	SA/2D Connections	Discussion of how to use SA/2D Connections in a 2D Flow Area	3.6 SA2D Connections.pdf
1500-1530	D3.7	Terrain Modifications Demonstration	Introduction to cloning a terrain and adding a simple terrain modification.
1530-1700	W3.8	SA/2D Connections	In this workshop, students will utilize 2D Connections (internal hydraulic structures) inside of a 2D Flow Area to improve the river hydraulics model by overriding terrain elevations.	3.8 Workshop - 2D Connections.pdf

Thursday

Time		Topic	Objective	Material
0800-0830		Review		3.8 WSolution - 2D Connections.pdf
0830-0900	L4.1	Simplified Bridge Modeling	Discussion on modeling a bridge using a 2D Connection using the 1D bridge modeling method.	4.1 Simplified Bridge Modeling in 2D Flow Areas.pdf
0900-1015	W4.2	Simplified Bridge Modeling Workshop	Students will utilize the 1D bridge modeling approach to modeling.	4.2 Workshop - Simplified Bridge.pdf
1015-1030		Break
1030-1100		Review		4.2 WSolution - Simplified Bridge.pdf
1100-1130	L4.3	Detailed Bridge Modeling	This lecture will cover how to use the new 2D Flow Area capability to perform very detailed multi-dimensional hydraulic analyses. Students will learn how to set up a model to get detailed water surfaces and velocities.	4.3 Detailed Bridge Modeling.pdf
1130-1230		Lunch
1230-1345	W4.4	Detailed Bridge Modeling Workshop	Students will develop a detailed bridge model to evaluate water surface elevations and velocities in detail.	4.4 Workshop - Detailed Bridge.pdf
1345-1415		Review		4.4 WSolution - Detailed Bridge.pdf
1415-1430		Break
1430-1515	L4.5	Precipitation and Wind	This presentation will discuss the use of the Precipitation and Wind boundary condition in HEC-RAS.	4.5 Precipitation Infiltration and Wind.pdf
1515-1615	D4.6	Precipitation and Wind Demonstration	Precipitation will be use to create a rain on grid model.
1615-1700	L4.7	1D/2D Direct Connections	Learn about hooking a 1D reach directly into a 2D Flow area, as well as having a 1D reach come out of a 2D Flow Area. The concept of 1D to 2D iterations will be introduced.	4.7 1D2D Direct Connections.pdf

Friday

Time		Topic	Objective	Material
0800-0830	L5.1	Introduction to the 3D Viewer	An introduction to RAS Mapper is provided, specifically for visualizing HEC-RAS results.	5.1 HEC-RAS 3D Viewer.pdf
0830-0900	D5.2	3D Viewer Demonstration	The 3D Viewer will be demonstrated
0900-1000	D5.3	RAS Mapper Demonstration	This demonstration highlights the various cool functionality in RAS Mapper including terrain modification, terrain resampling, data export, and data import.
1000-1130		Course Closing	Post-test, course evaluations, oral critique, and closing remarks