A Practical Introduction To 2D River Modelling In Hec-Ras

A step-by-step guide to building, running and interpreting 2D models using RAS Mapper in HEC-RAS

What you'll learn
Learn to work with RAS Mapper within the HEC-RAS software environment to create terrain layers for 1 and 2D river modelling.
Learn how to import 1D cross-section data and use it to create a more accurate channel. network.
Learn how to create Landcover Layers and apply Manning’s n values.
Learn how to create a 2D mesh, set cell parameters and add Refinement Regions and Breaklines.
Learn how to build Lateral Structures in order to connect 1D to 2D elements.
Learn how to adjust a 2D area to create an optimal river channel mesh.
Learn how to enter unsteady flow Boundary Condition data and Initial Conditions.
Learn how to set up an Unsteady Run and about Computation Options and Tolerances.
Learn how to pick an appropriate time-step using the Courant Number.
Learn how to view 1D and 2D results and understand what the outputs mean.
Requirements
A basic understanding of the concepts involved in river hydraulic modelling would be beneficial but the course learning goals can be achieved without the need for any prior experience of using HEC-RAS.
Description
In this course you will learn, through 54 short video tutorials, how to construct a combined 1D-2D and a 2D-only river model in the HEC-RAS hydraulic modelling software package. This course, builds on my Udemy 1D HEC-RAS modelling course but is stand-alone and you do not need to take that course in order to follow and complete this one although it would be useful to have a basic understanding of general hydraulic modelling concepts.All the data necessary to follow and build your models is supplied with this Udemy course and the HEC-RAS software itself is free to download from the web.Much of the tutorial and model build will focus on the use of the RAS Mapper module within the HEC-RAS software environment. You will learn how to import terrain model data, modify it using surface interpolation techniques and how to create landuse data layers to generate roughness data. You will then go on to learn about 2D geometry creation, how to set cell size and how to adjust cell spacing and alignment to best represent the underlying terrain and likely flow patterns and, in your first model, you will then go on to create a lateral structure to connect 1D to 2D areas. In the second model that you build you will also learn how to represent a main river-channel within a 2D model surface. You will then learn how to enter boundary condition flow data and how to run model scenarios. Several of the tutorials are then focused on discussing both 1D and 2D computation options and tolerances and also how to set the computation interval based upon the Courant Number. You will learn about these various aspects of modelling by making adjustments to your model and then viewing the impact had on the computed results output. Finally, you will learn how to view and manipulate both 1D results in the main HEC-RAS software environment and 2D outputs in RAS mapper along with tips on how to best interrogate and display the output data.This course will enable you to advance your hydraulic modelling skills from 1D-only simulations to 2D modelling within a geo-referenced terrain environment and as such it will stand you in good stead whether you study river channel processes in academia or work in the river engineering industry.

Overview

Section 1: Introduction

Lecture 1 Introduction

Lecture 2 Course Download Material

Lecture 3 HEC-RAS Installation

Lecture 4 Creating a New Project

Section 2: Creating a Terrain Model and Manning's n Layers

Lecture 5 Uploading a Projection File

Lecture 6 Uploading a Terrain Model

Lecture 7 Importing Geometry Data

Lecture 8 Creating Bank Lines

Lecture 9 Creating a New Terrain Layer

Lecture 10 Adding Map Data

Lecture 11 Creating a Manning's n Layer

Lecture 12 Manning's n Values and Classification Polygons

Lecture 13 Creating a User Defined Manning's Layer

Section 3: Building a 2D Geometry Layer

Lecture 14 2D Perimeter Creation

Lecture 15 Geometry Editing Tools

Lecture 16 2D Area Mesh Updates and Hydraulic Properties

Lecture 17 Breaklines

Lecture 18 Refinement Regions

Lecture 19 Manning's n Calibration Regions

Lecture 20 Managing Associations

Lecture 21 Cell Generation and Hydraulic Properties Tables

Section 4: Building a Lateral Structure

Lecture 22 Lateral Structure 1

Lecture 23 Lateral Structure 2

Lecture 24 Lateral Structure 1 Data

Lecture 25 Lateral Structure 2 Data

Section 5: Usteady Flow Data, Computation Setup and Calculation Options

Lecture 26 Unsteady Flow Data Entry

Lecture 27 Unsteady Flow Computation Setup

Lecture 28 Calculation Options 1

Lecture 29 Calculation Options 2

Lecture 30 Calculation Options 3

Lecture 31 Performing an Unsteady Run

Section 6: Model Results

Lecture 32 1D Results Part 1

Lecture 33 1D Results Part 2

Lecture 34 2D Results Part 1

Lecture 35 2D Results Part 2

Lecture 36 2D Results Part 3

Section 7: Adjusting Computation Factors and the Courant Number

Lecture 37 Adjusting 1D Computation Factors

Lecture 38 Adjusting 2D Equations

Lecture 39 Adjusting 2D Computation Options

Lecture 40 Selecting an Appropriate Time Step

Lecture 41 Adaptive Time Step Selection

Section 8: Creating a 2D-Only Model

Lecture 42 Creating a Copy of Your Model

Lecture 43 Creating a New 2D Flow Area

Lecture 44 Channel Refinement Region

Lecture 45 Refinement Region Cell Sizing

Lecture 46 Channel Centre Breakline

Section 9: Boundary Condition Data, Unsteady Flow Simulation and Results

Lecture 47 Boundary Condition Lines

Lecture 48 Discussion about Boundary and Initial Conditions

Lecture 49 Boundary Condition Data

Lecture 50 Unsteady Flow Simulation and Results

Lecture 51 Unsteady Flow Simulation with Adjusted Roughness

Section 10: The RASter Calculator, Conclusions and 3D Viewing

Lecture 52 The RASter Calculator

Lecture 53 Conclusions: When to Use 1D and 2D Models

Lecture 54 Bonus Lecture - The 3D Viewer

Section 11: UPDATES: Geometry data manipulation

Lecture 55 Entering and processing geo-referenced 1D cross-section data for RAS Mapper

Lecture 56 Extracting 1D cross-section data from a high resolution terrain model

Those interested in advancing their hydraulic modelling skills from 1D to 2D modelling using RAS Mapper within the HEC-RAS software package.