Water Resources Modeling and GIS

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

Model

HEC-RAS and Geo-RAS

M___, 2016

Model

• Utilize HEC Geo-RAS to import data into RAS

HEC-RAS

• River Analysis System

• Developed by Hydrologic Engineering

Center (HEC)

• One dimensional steady and unsteady • 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”– 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)• 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)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• 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 floodplain TINs

• Creates depth and velocity maps

– Saves time on data presentation

HEC GeoRAS (Post Processing)

HEC GeoRAS (Floodplain Delineation)