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Enhancements and Modifications to the Full Equations (FEQ) Model, March 1995 to August 1999
Note: This document is separate from the U.S. Geological Survey report by Franz and Melching (1997). This description of enhancements and modifications to the Full Equations Utilities Model has not been approved by the Director of the U.S. Geological Survey.

Input description update for section 13.10 Input Files Block - Input File Table, Franz and Melching 1997a, p. 185

Section 13.10 Input files Block--Input File Table

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This block gives the names of files for FEQ to use in retrieving time series for input at nodes where a time-dependent boundary condition is required. There are two different sources for an input time series in this block: a point time series file (PTSF) or the path name in a HEC DSS file. There is no convenient way to give both a file name for the DSS file and its path name on a single line of input. Therefore FEQ assumes that the character string given in the NAME field is the file name of a PTSF unless it has already encountered a HEC DSS file name given on a line following the special keyword, HECDSS=. If FEQ has found such a line, all character strings given under the NAME field are taken to be path names for the current HEC DSS file name. The HEC DSS file name applies to all NAME values that appear in subsequent lines. To clear the HEC DSS file name give a blank value for the HEC DSS file name. The keyword for HEC DSS file names must start in column 1 and must be in upper case.

LINE 1

Variable: HEAD
Format: A80
Example: UNIT NAME
Explanation:
User supplied heading for subsequent information.

LINE 2

Variables: UNIT, NAME
Format: I5, 1X, A64
Explanation:
Specifies either a Point Time Series File (PTSF) or the path name of a HEC DSS file to use in obtaining the time series of boundary node values of flow or elevation. FEQ distinguishes these two cases based on the appearance of the HEC DSS file name keyword, HECDSS=, in an earlier line of input with a valid HEC DSS file name following the equal sign. This starts HEC DSS path name mode. All lines of input following the line containing the HEC DSS file name keyword are assumed to refer to path names in that DSS file. All DSS time series must have a type of INST-VAL. In either case UNIT gives the absolute value of the unit number given with Code=6 in the Network Matrix Control Input entry. This number is a time-series id number and is no longer used, as in previous versions, for the details of Fortran file handling. The UNIT number is a time-series id number assigned by the user but the old name is retained for the time being. The default limit is 250. The UNIT number used must be unique and apply to only one file name in this block FEQ checks for such duplication and will report an error if any are found.
Line 2 is repeated for each input file required. The table is terminated if a negative value for UNIT is given. The table must be present even if there are no input files. The table is then null consisting of only the heading and a-1 in the UNIT column. Each input file is associated with a single exterior node by giving the negative of the unit number in the source field for a forced boundary condition (CODE=6) in the Network-Matrix Table.
This means of specifying point inflows can be used with or without a DTSF present if DIFFUS=YES. If a DTSF is used it is the responsibility of the user to ensure that all needed time segments are in the file. The input/output file system was designed to permit subdivision of a large stream system at points of known hydraulic control such that a series of smaller stream systems could be analyzed in sequence from upstream to downstream to represent the larger system. The output from an upstream subsystem would be stored in a file for later use as input to the downstream system. For this approach to work properly several conditions must be satisfied. First, the same DTSF must be used for all subsystems to ensure that the same length and sequence of time segments appears in all input/output files. Second, the points of subdivision must be at points of known relationship between flow and stage in the stream. If this is not the case, then the subdivision of the system into smaller parts will distort the results. If no such points can be found then the system should not be subdivided.

Left ArrowBack to Franz and Melching (1997a), p. 185, section 13.10, Input Files Block-- Input File Table