OHD/HL/HSMB - Hydraulics: Tools

The Guidelines for the Transition from FLDWAV to HEC-RAS; Forecast Implications and Transition Tools describes key differences between FLDWAV (and DWOPER) and HEC-RAS and procedures to convert FLDWAV models to HEC-RAS. It also summarizes information about RFCs FLDWAV models and provides a detailed explanation of which features can be converted, which features can be overlooked in the conversion process and why. We analyzed a number of model variants to understand the relative importance of different model features and the simulation differences after conversion. This helped to guide development of the conversion tools. To assist in efforts to check converted models in simulation mode and refine calibrations, we also describe Python scripts that can be used to convert existing flow and stage time series to HEC-RAS compatible format and compute statistics on simulated time series.

Conversion Tools

fld2ras.f

In order to represent the symmetric cross-sections of FLDWAV in HEC-RAS, the BS versus HS pairs are translated to station versus elevation. We developed a FORTRAN program called fld2ras to convert FLDWAV cross-sections to HEC-RAS. Section 4.1 of the Guidelines Document describes how to compile and use this program.

oh2dss.py and oh2dss_bat.py

Transitioning existing FLDWAV or DWOPER models to HEC-RAS for simulation mode may require conversion of the FLDWAV cross-sections to HEC-RAS geometry files and conversion of stage and flow time-series data into DSS format. The oh2dss Python script converts several ASCII formats (including those typically used by FLDWAV) into DSS format. Oh2dss is run within HEC-DSSVue v. 1.2 software. See Section 4.2 of the Guidelines Document on how to convert flow and stage time series data from typical FLDWAV formats into DSS format. Note that this script works only with DSSVue v. 1.2.

eventstats.zip

The Python script eventstats_bat.py calculates several statistics comparing simulated and observed stage simulations at numerous points along a river system. See Section 7 of the Guidelines Document for more details. The Zip file available here contains example control files used by the program but does not contain actual time series input files.