Hydraulic Engineering Center - River Analysis System
A computer modeling
program produced by the Army Corps of Engineers
. HEC-RAS is used for generating profiles of the flood plain
for a particular stream or river.
concerning the stream and its major features are gathered using existing topographic map
s, aerial photography
, and field reconnaissance
. Cross-sections of the stream and measurements of bridges or culverts are entered into the system. Hydrologic data
(basically just flow rate
s) are generated using another program, often HEC-HMS
or its predecessor, HEC-1
. Typical storm events that are studied are the 10, 25, 50, 100, and 500-yr storms. This information is also entered into the system.
HEC-RAS performs lots of maths on this data and generates water levels for the stream. These water levels are used for many purposes, such as flood insurance
, emergency planning, and municipal codes on new construction.
HEC-RAS is a GUI
replacement for HEC-2
, with many new features and updated formulae. HEC-RAS version 3.0.1 was released in April 2001. Haestad
Methods, Inc. distributes and supports this software.
Sources: Me, HEC-RAS about file, HEC-RAS Application Guide.