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Workflow Processes:

• Create Geometric Data

  Geometric Data files is where HEC-RAS stores all the geometry for your HEC-RAS project. This includes River, Bank Lines, Cross Sections, 2D Flow Areas, Storage Areas, etc.. HEC-RAS projects can have one, or many, geometric data files. At any given time, you can open the geometric data you want to work with either in RAS Mapper or the Geometric Data window.
  In this process we’ll address how to create a geometric data file, sketch a river with multiple reaches, acquire existing cross section data from a terrain, create a bridge and inline structure, and perform an unsteady flow simulation.
  NOTES:
  Geometric Data can be created and editing in RAS Mapper and/or the Geometric Data window. For some circumstances, a particular method might be preferred and/or recommended. This workflow mostly leverages RAS Mapper for more layout driven tasks, and the Geometric editor for hydraulic inputs.

  REFERENCES:
  To help you understand these concepts better, view the how-to videos on:
  Define River Schematic for 1D Hydraulic Modelings
  Add Tributaries and Cross Sections
  River Setup and XS Interpolation
  Visualize Interpolated Reaches and Place Structur(es)
  Unsteady Flow Simulation

• Setup Flood Plain Modeling

  HEC-RAS was developed for the purpose of Floodplain modeling, and many of the geometric features are required to model the hydraulic conditions for major flow events. The most common tasks needed for floodplain modeling are outlined in this process, although many more tools and capabilities can be found in the software.
  In this process we’ll address how to create and modify 2D flow areas, make common terrain modifications, add lateral structures, connect 2D Flows areas to 1D hydraulic elements, and model a bridge within a 2D flow area.

  REFERENCES:
  To help you understand these concepts better, view the how-to videos on:
  2D Mesh for Hydraulic Modeling
  2D Mesh for Hydraulic Modeling – Editing Part 1
  2D Mesh for Hydraulic Modeling – Editing Part 2
  Terrain Modification – Part 1
  Terrain Modification – Part 2
  2D Flow Areas to 1D Hydraulic Elements Connection
  2D Flow Areas to 1D Hydraulic Elements Connection
  Modeling Bridges Inside 2D Flow Areas
  RAS Mapper Useful Tools for Every Project – Part 1
  RAS Mapper Useful Tools for Every Project – Part 2

• Getting Started in HEC-RAS

  To get started in HEC-RAS you need to download software. You will find the HEC-RAS software download on the US Army Corps of Engineers website.

  Once installed, you can access HEC-RAS via a desktop shortcut. Upon opening HEC-RAS, you’ll be see the main application interface.

  Getting_Started_in_H_001

  To start a new project in HEC-RAS, create a folder where you want your project to live. There should only be one HEC-RAS project per folder, and each project should have an intuitive name. With each HEC-RAS project you’ll need to create one or more geometric data files, along with plan, steady, and unsteady flow files. Files you create for your HEC-RAS project should be saved in the same project folder to make sharing and archiving projects easier.

  REFERENCES:
  To help you understand these concepts better, view the how-to videos on:
  HEC-RAS Introduction

• Establish Existing Conditions

  For HEC-RAS projects, existing condition data is essential to developing and analyzing hydraulic models. The existing conditions can be acquired from USGS maps, or from DEM files provided from external sources. Georeferenced data can also be imported from Shapefiles, if available. Prior to creating the existing conditions for your project, you must set the units for your project, and assign a projection system. The terrain data can then be downloaded and/or imported into your project, along map imagery to provide context for the existing conditions.
  REFERENCES:
  To help you understand these concepts better, view the how-to videos on:
  Starting a New Project
  Import Terrain Data