Artur Llansà

20. FLDWAV MODEL INPUT1
The FLDWAV model requires an input file created by the user. Documentation of the
data input structure for the FLDWAV model is given in this Section 20. The data is free
formatted, i.e., numbers are separated by spaces or commas. Unlike the DAMBRK and
DWOPER models which have fixed formatted input structures, all parameter values required by
FLDWAV must be entered.Parameters that would normally be left blank must be entered as zero
values. Decimal points are required only if the value being entered contains a decimal. Although
there is no card coding, the user may add comments for each data group prior to entering the data
for the group. In lieu of comments, the user may enter a blank line prior to each data group. A
blank line or comment line must beentered before each data group except data groups 0-1, 0-2,
and 89. Note: Data sets for the Beta version of FLDWAV will not run on this version
(November 1998) of FLDWAV without modification because additional parameters have
been added.
20.1 Input Data Structure and Data Variable Definition for FLDWAV Model
Data Variable
Group Name

Contents

0-1*

MSG

Description of the data set. Amaximum of 20 lines is allowed,
the last line must be EOM. Each line may have a maximum of 72
characters.

0-2*

DESC

Type of output display. For echo print of the input parameters,
enter 'NODESC.' For a description of the model parameters,
enter 'DESC'.

1*

EPSY

Depth tolerance in Newton-Raphson Iteration scheme (0.001-1.0
ft). A good value is 0.01 ft.

THETA

Accelerationfactor in solving tributary junction problem (0.51.0). Varies with each problem. A good first choice is 0.8.

F1

2 weighting factor (0.5-1.0) in finite difference technique. A
good value is 0.6.

XFACT

Factor to convert units describing the location of the
computational points along the routing reach to feet; e.g., if units
are in (mi), XFACT = 5280. When using metric units, thisfactor
converts the units to meters: e.g., if units are in (km),

*
Input data group required for any simulation.
** Input data group required for any dam break simulation
DG Abbreviation for Data Group
20.1

Data Variable
Group Name

Contents
XFACT=1000.

DTHYD

Time interval (hr) of all input hydrographs. If time interval is not
constant, set DTHYD = 0. If running in NWSRFS (notin standalone mode), set DTHYD > 0.

DTOUT

Time interval (hr) of all output hydrographs. If running in standalone mode (not a part of NWSRFS), set DTOUT = 0.

METRIC

Parameter indicating if input/output is in English (METRIC = 0)
or Metric (METRIC = 1) units. All computations within
FLDWAV are done in English units; only the input/output may
be displayed in metric units. See Table 20.1for units conversion
information.

Table 20.1. English/Metric Equivalents
Conversion Factor
(English to Metric)

Property

English Unit

Metric Unit

Time

hr

hr

Length

ft

m

1/3.281

Length

mile

km

1.6093

Flow

ft3/sec

m3/sec

1/35.32

Area

ft2

m2

1/10.765

Surface Area

acres

km2

1/247.1

Volume

acre-ft

106m31/810.833

Weir Coef.

ft1/2/sec

m1/2/sec

1/1.811

Unit Weight

lb/ft3

N/m3

157.1

Shear Strength

lb/ft2

N/m2

47.88

Viscosity (Dynamic)

lb sec/ft2

N sec/m2

47.88

Manning n

English and Metric are same

20.2

Data
Group

Variable
Name

Property

Contents
English Unit

Metric Unit

Conversion Factor
(English to Metric)

Note: Althoughthe documentation refers to English units only, the metric option
is fully functional. This table should be used to determine comparable units
and to convert the recommended values to metric units.
2*

JN

Total number of rivers in the system being routed
simultaneously.

NU

Number of values associated with observed hydrographs.

ITMAX

Maximum number of iterations allowed in...