Using GIS with HEC RAS

HEC-RAS has the ability to import three-dimensional river schematic and cross section data created in a GIS or CADD system.While the HEC RAS software only utilizes two dimensional data during the computations,the 3D information is used in the program for display purposes.After the user has completed a hydraulic analysisi,the computed water surface profiles can be exported back to the GIS or CADD system for development and display of a floodplain map.
The importing and exporting of GIS or CADD data is accomplished through the use of formatted ASCII text files,The text files provide a generic way of exchanging data between GIS/CADD systems and HEC -RAS,without adopting any single GIS/CADD system.
The HEC has developed a set of macros for Arc Info(using Arc Macro Language,AML) that will allow a user to write the geometric data in the required format as well as read the HEC-RAS results and perform the floodplain mapping.

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