CEE 795Water Resources Modeling and GIS

Learning Objectives:• Describe the HEC-River Analysis System (RAS)

Model• Utilize HEC Geo-RAS to import data into RAS

Handouts:Ras-example.doc

Assignments:Exercise #6

Lecture 7: HEC-RAS and Geo-RAS

March 6, 2006

HEC-RAS

• River Analysis System

• Developed by Hydrologic Engineering Center (HEC)

• One dimensional steady and unsteady flow analysis

• Subcritical, supercritical, and mixed flow regime calculations

HEC-RAS cont.

• Manual Data Input Required– stream centerline– cross sections– Manning’s “n”– flow data

Main Menu

Geometric Data (stream configuration)

Cross Sections

Table Output

Profiles

HEC GeoRAS

• Pre-RAS processor– Creates HEC-RAS input file– Input Needs

• Triangular Irregular Network (TIN)

• Land Use Data

HEC GeoRAS

• Developed by Hydrologic Engineering Center (HEC)

• pre and post Data Processor for the River Analysis System (HEC-RAS)

HEC GeoRAS(creating a TIN from topography)

HEC GeoRAS(creating a TIN from topography)

HEC GeoRAS(input Triangular Irregular Network)

HEC GeoRAS

• Pre-RAS processor – Saves time on data input

• no manual cross section entry

• no manual Manning’s “n” entry

HEC GeoRAS (Pre-Processing)

Centerline

Banks

Cross Sections

HEC GeoRAS (Cross Section)

HEC GeoRAS

• Post-RAS processor– Accepts HEC-RAS output file– Output Formats

• Creates floodplain TINs

• Creates depth and velocity maps

– Saves time on data presentation

HEC GeoRAS (Post Processing)

HEC GeoRAS (Floodplain Delineation)