FLOOD05523

• County: Statewide
• Basin: Statewide
• Title: HEC-RAS River Analysis System
• Date: 2/1/1995
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Educational/Technical/Reference Information

Chapter I Introduction

General Philosophy of the Modeling System

HEC-RAS is an integrated system of software, designed for interactive use in
a multi-tasking, multi-user network environment. The system is comprised
of a graphical user interface (Gill), sepamte hydraulic analysis components,
data storage and management capabilities, graphics and reporting facilities.

The system contains three one-dimensional hydraulic analysis components
for: (1) steady flow water surface profile computations; (2) unsteady flow
simulation; and (3) movable boundary sediment transport computations. A
key element is that all three components use a common geometric data
representation and common geometric and hydraulic computation routines.
In addition to the three hydraulic analysis components, the system contains
several hydraulic design features that can be invoked once the basic water
surface profiles are computed.

The current version of HEC-RAS only supports Steady Flow water surface
profile calculations. New features and additional capabilities will be added
in future releases.

Overview of Program Capabilities

HEC-RAS is designed to perform one-dimensional hydraulic calculations for
a full network of natural and constructed channels. The following is a
description of the major capabilities ofHEC-RAS.

User Interface

The user interacts with HEC-RAS through a graphical user interface (Gill).
The main focus in the design of the interface was to make it easy to use the
software, while still maintaining a high level of efficiency for the user. The
interface provides for the following functions:

. File management

. Data entry and editing

. Hydraulic analyses

. Tabulation and graphical displays of input and output data

. Reporting facilities

. On-line help

1-2