Water Resources Surface Water Software: Full Equations (FEQ) Model Web Resources

FEQ: Full Equations model

Diffuse Time Series File (DTSF), Point Time Series File (PTSF), and Initial Conditions file format changes

Point time-series files (PTSF's) are now read and written as direct-access unformatted. This change allows these files to move among various operating systems and compiled executables. This has been tested on five different compilers (two under Linux and three under MS Windows). PTSF's created with earlier versions of FEQ must be converted using the PTSFUTL utility or the models that generated the PTSFUTL must be rerun with FEQ version 10.20 or later.

Diffuse time-series files (DTSF's) are now read by FEQ as direct-access unformatted. This change was made to allow these files to move among the various operating systems and compilers, similarly to the PSTF's. Old files must be converted using the version of TSFUTL included in the FEQ 10.60 release package. HSPF 12.0 allows a direct output to the new unformatted DTSF using the PLTGEN routine.

The GETIC and PUTIC files have been updated to be written and read using direct access statements. This means that old forms of these files cannot be used with this version. The files have been expanded to support additional control structures as well, so old files are obselete for that reason as well.

Side weir optional table definition change

The definition of the flow-factor adjustment table in the side-weir instruction, code=14, when it appears with a crest level adjustment table is changed. When both optional tables are present, FEQ does the following:

• (1) Computes the flow at the head at current crest level = Q1
• (2) Computes the flow at the head at original fixed crest level = Q2
• (3) Finds the current flow factor, fac, from the flow-factor table.
• (4) Computes the flow as:

Q = fac*Q1 + (1 - fac)*Q2

This approximates the combination of flow over the portion of the flow surface that is at its original level and the flow through the portion of the flow surface that is at its new level. This computation assumes the crest is approximately horizontal and that the flow interaction between the two flows is small. The factor is estimated by the ratio of the length of weir that is being shifted by erosion of the surface to the total overflow weir segment. Previously, this time series table consisted of factor values determined by the user.

FEQUTL: Full Equations Utilities model

BRIDGE routine no longer available

The obsolete BRIDGE routine is no longer available. Function tables for bridges (table type 14) are computed using the WSPROQZ command documented in Franz and Melching (1997) with additional notes accessible using the FEQ Web Resources search utility

U.S. Department of the Interior | U.S. Geological Survey | Illinois Water Science Center
URL: http://il.water.usgs.gov/proj/feq/impt_notice.shtml
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