HEC-RAS Online Help - Linear Routing Option

HEC-RAS Online Help

Linear Routing Option

The user can choose to use a linear routing option instead of entering structure information and having the program compute the flow from the structures. The linear routing option is selected by going to the Structure Type pull down and selecting “Linear Routing” from the list. This option uses a coefficient times the difference in available storage between the too and from connection. When this option is selected, a linear routing button will appear on the left side of the window. Selecting the linear routing button will bring up the following window:

Figure 6.43 Simple Spillway Data Editor

As shown in the Linear Routing editor, the user must enter a linear routing coefficient for both the positive and negative flow directions. Additionally, the minimum elevation of the spillway crest must be entered. If both water surfaces go below the spillway crest, no flow is passed over the structure.

Introduction

General Philosophy of the Modeling System

Overview of Program Capabilities

Hydraulic Analysis Components

Data Storage and Management

Graphics and Reporting

Installing HEC-RAS

Hardware and Software Requirements

Installation Procedure

Uninstall Procedure

Working With HEC-RAS - An Overview

Starting HEC-RAS

Steps in Developing a Hydraulic Model with HEC-RAS

Starting a New Project

Entering Geometric Data

Entering Flow Data and Boundary Conditions

Performing the Hydraulic Computations

Viewing and Printing Results

Importing HEC-2 Data

What You Should Know First

Steps for Importing HEC-2 Data

Reproducing HEC-2 Results

Getting and Using Help

Example Application

Starting a New Project

Entering Geometric Data

Drawing the Schematic of the River System

Entering Cross Section Data

Entering Junction Data

Saving the Geometry Data

Entering Steady Flow Data

Performing the Hydraulic Calculations

Viewing Results

Printing Graphics and Tables

Sending Graphics Directly to the Printer

Sending Graphics to the Windows Clipboard

Sending Tables Directly to the Printer

Sending Tables to the Windows Clipboard

Exiting the Program

Working With Projects

Understanding Projects

Elements of a Project

Steady Flow Data Files

Unsteady Flow Data Files

Sediment Data Files

Hydraulic Design Data Files

Creating, Opening, Saving, Renaming, and Deleting Projects

Project Options

Entering and Editing Geometric Data

Developing the River System Schematic

Building The Schematic

Adding Tributaries into an Existing Reach

Editing The Schematic

Interacting With The Schematic

Background Pictures.

Cross Section Data

Entering Cross Section Data

Editing Cross Section Data

Cross Section Options

Plotting Cross Section Data

Stream Junctions

Entering Junction Data

Selecting A Modeling Approach

Bridges and Culverts

Cross Section Locations

Contraction and Expansion Losses

Bridge Hydraulic Computations

Entering and Editing Bridge Data

Bridge Design Editor

Culvert Hydraulic Computations

Entering and Editing Culvert Data

Bridge and Culvert Options

Bridge and Culvert View Features

Multiple Bridge and/or Culvert Openings

Entering Multiple Opening Data

Defining The Openings

Multiple Opening Calculations

Inline Structures (Weirs and Gated Spillways)

Entering and Editing Inline Structure Data

Lateral Structures (Weirs, Gated Spillways, Culverts, and Diversion Rating Curves)

Entering and Editing Lateral Structure Data

Linear Routing Option

Storage Area Connections

Cross Section Interpolation

Entering and Editing Ice Data

Entering Ice Data at a Cross Section

Entering Ice Data Through a Table

Entering Ice Data at Bridges

Setting Tolerances for the Ice Jam Calculations

Viewing and Editing Data Through Tables

Manning's n or k values

Contraction and Expansion Coefficients

River Stationing

Node Descriptions

Picture File Associations

Bridge Width Table

Weir and Gate Coefficient Table

Importing Geometric Data

USACE Survey Data Format

HEC-2 Data Format

HEC-RAS Data Format

UNET Geometric Data Format

MIKE11 Cross-Section Data

Geometric Data Tools

Graphical Cross Section Editor

Reverse Stationing Data

Set Ineffective Areas to Permanent Mode

Cross Section Points Filter

Fixed Sediment Elevations

GIS Cut Line Check

View Reach Connectivity

Datum Adjustment

Fix Overlapping Ineffective Areas

GIS Coordinates

Plot GIS Reach Bounds

Attaching and Viewing Pictures

Saving the Geometric Data

Performing a Steady Flow Analysis

Entering and Editing Steady Flow Data

Steady Flow Data

Boundary Conditions

Steady Flow Data Options

Saving The Steady Flow Data

Importing Data From The HEC Data Storage System (HEC-DSS)

Performing Steady Flow Calculations

Defining A Plan

Saving The Plan Information

Simulation Options

Starting the Computations

Performing an Unsteady Flow Analysis

Entering and Editing Unsteady Flow Data

Unsteady Flow Data

Boundary Conditions

Flow Hydrograph:

Stage Hydrograph:

Stage and Flow Hydrograph:

Lateral Inflow Hydrograph:

Uniform Lateral Inflow Hydrograph:

Groundwater Interflow:

Time Series of Gate Openings:

Elevation Controlled Gate:

Navigation Dam:

Internal Observed Stage and Flow Hydrograph:

Initial Conditions

Unsteady Flow Data Options

Saving The Unsteady Flow Data

Performing Unsteady Flow Calculations

Defining A Plan

Selecting Programs to Run

Geometric Pre-Processor

Unsteady Flow Simulation

Simulation Time Window

Computation Settings

Simulation Options

Saving The Plan Information

Starting the Computations

Calibration of Unsteady Flow Models

Observed Hydrologic Data

River and Floodplain Geometry

Roughness Coefficients

River and Floodplain Storage

Hydraulic Structure Coefficients

Steps To Follow in The Calibration Process

General Trends When Adjusting Model Parameters

Calibration Suggestions and Warnings

Model Accuracy, Stability, and Sensitivity

Model Stability

Model Sensitivity

Viewing Results

Cross Sections, Profiles, and Rating Curves

Viewing Graphics on the Screen

Graphical Plot Options

Plotting Velocity Distribution Output

Plotting One Variable Versus Another

Sending Graphics to the Printer or Plotter

Sending Graphics to the Windows Clipboard

Stage and Flow Hydrographs

X-Y-Z Perspective Plots

Tabular Output

Detailed Output Tables

Detailed Output Table Options

Profile Summary Tables

User Defined Output Tables

Sending Tables to the Printer

Sending Tables to the Windows Clipboard

Viewing Results From the River System Schematic

Viewing Ice Information

Viewing Graphical Ice Information on the Screen

Viewing Tabular Ice Information

Viewing Data Contained in an HEC-DSS File

Exporting Results To HEC-DSS

Performing a Floodplain Encroachment Analysis

Entering Floodplain Encroachment Data

Performing The Floodplain Encroachment Analysis

Viewing the Floodplain Encroachment Results

Floodway Encroachments With Unsteady Flow

Troubleshooting With HEC-RAS

Built in Data Checking

Checking the Data as it is Entered

Data Checking Before Computations are Performed

Errors, Warnings, and Notes

Steady Flow Log Output

Unsteady Flow Log Output

Viewing The Log File

Reviewing and Debugging the Normal Output

Viewing Graphics

Viewing Tabular Output

The Occurrence of Critical Depth

Computational Program Does Not Run To Completion

Computing Scour at Bridges

General Modeling Guidelines

Entering Bridge Scour Data

Entering Contraction Scour Data

Entering Pier Scour Data

Entering Abutment Scour Data

Computing Total Bridge Scour

Performing Channel Modifications

General Modeling Guidelines

Entering Channel Modification Data

Performing the Channel Modifications

Comparing Existing and Modified Conditions

Using GIS Data With HEC-RAS

General Modeling Guidelines

Importing GIS or CADD Data Into HEC-RAS

Completing The Data and Performing The Computations

Completing The Geometric Data

Entering Additional Cross Section Data

Performing The Computations and Viewing Results

Exporting Computed Results To The GIS or CADD

Stable Channel Design Functions

General Modeling Guidelines

General Command Buttons

Uniform Flow Computations

Solving for Slope, Discharge, or W/S Elevation

Solving for Bottom Width

Applying Uniform Flow Data to the Geometry File

Saving Uniform Flow Data

Stable Channel Design

Copeland Method

Tractive Force Method

Sediment Transport Potential

Advanced Features for Unsteady Flow Routing

Mixed Flow Regime

Dam Break Analysis

Entering Dam Break Data

Estimating Dam Break Parameters

HEC-RAS Output For Dam Break Analyses

Levee Overtopping and Breaching

Modeling Pump Stations

Navigation Dams

Pool Only Control

Hinge Point Only Control

Hinge Point and Minimum Pool Operations

Hinge Point and Minimum and Maximum Pool Control

Appendix A References

Supported HEC-RAS Data Exchange

The Import/Export Data File Structure

Records and Keywords

HEC-RAS Channel Geometry Import File

HEC-RAS Model Results Export File

Water Surface Bounding Polygon

Import/Export Guidelines

Defining The Stream Network

Defining Cross Sections

Sample HEC-RAS Geometry Import File

Sample HEC-RAS Geographic Data Export File

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