Water Resources Applications Software
Summary of DAFLOW
NAME
daflow - Streamflow routing in upland channels or channel networks
ABSTRACT
DAFLOW is a digital model for routing streamflow using the diffusion
analogy form of the flow equations in conjunction with a Lagrangian
solution scheme. The flow model is designed to provide reasonable
predictions of discharge and transport velocity using a minimum of
field data and calibration. The use of hydraulic geometry
coefficients for area and top width is believed to contribute to the
model's predictive capability. The flow model is designed to
support the BLTM transport model documented by Jobson and
Schoellhamer (1987), which simulated the fate and movement of
dissolved water-quality constituents through a network of upland
streams and rivers. It also should be useful for routine flow
routing applications.
DAFLOW is included in the BLTM distribution and also available
separately as a DAFLOW distribution containing the following
programs:
daflow - diffusion analogy flow model
wdaflo - diffusion analogy flow model, use either flat file or
wdm data base
flwopt - computes RMS errors to optimize hydraulic coefficients
bdaflow - build the input file for DAFLOW
cel - compute coefficients for area and width equations
intrp - interpolates data to an even interval
unit - reads unit values from adaps and uses a rating table to
do something
flwplt - estimate ungaged inflow and plot
METHOD
DAFLOW routes flow through a system of open channels and generates
output that can be used to drive a transport model such as LTM or
BLTM. The program solves the diffusion analogy form of the flow
equations and therefore should not be used where backwater effects
are significant or where flow reversals occur. The program is very
simple and stable. The model has only two adjustable coefficients
per branch (the wave celerity and wave attenuation coefficient), and
these must remain constant. DAFLOW input and output is to flat
files, but auxiliary programs to input data and plot results are
available. The program generates a file containing the discharge,
cross-sectional area, top width, and tributary inflow at each grid
point and time step.
DAFLOW uses a flat file format for the input and output of time-
series data. A modified version of the program WDAFLO supports both
the flat file formats and the Watershed Data Management (WDM) file.
HISTORY
Version 1.2 1996/11/04 - In daflow.f, the code was incorrectly
checking the value of IERR for 1 rather than 21, causing the code
to fail to print the error message for too many waves in a
branch. Code was corrected.
Version 1.1 1995/04/11 - The daflow program was changed to read in
slope instead of wave dispersion coefficient. This allows the
program to vary the wave attenuation with discharge; the bdaflow
program was changed to ask for slope values rather than
dispersion.
The cel program was modified to add a new option to adjust W2
holding the width constant. For the first two options it also
computes coefficients based on channel forming discharge. It no
longer asks for a characteristic discharge. It also computes a
representative wave length and a wave length value needed for
smooth results.
Version 1.0 1995/02/08 - The cel program was modified to include two
methods for computing W1: from measured width (option 0) or from
channel forming discharge (option 1, the original method).
The daflow program was changed to correct a problem that occurred
in selecting the range of flows for estimation in the trial error
solutions for the discharge in the mixed wave. The problem
occurred when you had a tributary extracting more flow than
exists in the smallest wave.
1993/06 - The program wdaflo (a modified version of daflow) was
developed to support the use of the Watershed Data Management
(WDM) file for storage and management of input and output time-
series data.
DATA REQUIREMENTS
(1) Network description including branch lengths, wave celerity, and
wave attenuation. (2) Inflow hydro graphs at the upstream boundaries
and at tributaries input from either a flat file (DAFLOW or WDAFLO
or from a WDM file (WDAFLO).
OUTPUT OPTIONS
DAFLOW and WDAFLO both generate a flat file containing the
discharge, cross-sectional area, top width, and tributary inflow at
each grid point and time step; this format is compatible with BLTM
input require ments. WDAFLO will also write the discharge to a WDM
file.
SYSTEM REQUIREMENTS
DAFLOW is written in Fortran 77 with the following extensions:
include files and variable program names longer than 6 characters.
WDAFLO uses the UTIL, ADWDM, and WDM libraries from LIB. A subset of
these libraries is provided with the code and may be used instead of
the libraries; this subset uses INTEGER*4 and mixed type
equivalence. For more information, see System Requirements in LIB.
FLWPLT may be implemented with a user-supported Computer Associates
DISSPLA library or the LIB libraries GRAPH, UTIL, and STATS.
DOCUMENTATION
Jobson, H.E., 1989, Users manual for an open-channel streamflow
model based on the diffusion analogy: U.S. Geological Survey
Water-Resources Investigations Report 89-4133, 73 p.
REFERENCES
Bulak, J.S., Hurley, N.M., Jr., and Crane, J.S., 1993, Production,
mortality, and transport of striped bass eggs in Congaree and
Wateree Rivers, South Carolina: American Fisheries Society
Symposium 14, 1993, p. 29-37.
Hurley, N.M., Jr., 1991, Transport simulation of striped bass eggs
in the Congaree, Wateree, and Santee Rivers, South Carolina:
U.S. Geological Survey Water-Resources Investigations Report
91-4088, 57 p.
Jobson, H.E., 1985, Modeling temperature, BOD, DO and the nitrogen
cycle in the Chattahoochee River, Georgia, using the land flow
model: U.S. Geological Survey Water-Supply Paper 2264.
Jobson, H.E., 1987, Modeling dye and gas transport in the Missouri
River, Nebraska, the Madison effluent channel, Wisconsin, and
Trinity River, Texas: Water Resources Research, v. 23, no. 1.
Jobson, H.E., and Schoellhamer, D.H., 1987, Users manual for a
Branched Lagrangian transport model: U.S. Geological Survey
Water-Resources Investigations Report 87-4163, 73 p.
Wiley, J.B., 1992, Flow and solute-transport models for the New
River in the New River Gorge National River: U.S. Geological
Survey Open-File Report 92-65, 53 p.
Wiley, J.B., 1993, Simulated flow and solute transport and
mitigation of a hypothetical soluble-contaminant spill for the
New River in the New River Gorge National River, West Virginia:
U.S. Geological Survey Water-Resources Investigations Report
93-4105, 39 p.
TRAINING
Modeling Flow and Transport in a Riverine Environment (ID2020TC),
offered annually at the USGS National Training Center.
CONTACTS
Operation:
U.S. Geological Survey
Office of Surface Water
Harvey Jobson
415 National Center
Reston, VA 20192
hejobson@usgs.gov
Distribution:
U.S. Geological Survey
Hydrologic Analysis Software Support Program
437 National Center
Reston, VA 20192
h2osoft@usgs.gov
Official versions of U.S. Geological Survey water-resources analysis
software are available for electronic retrieval via the World Wide
Web (WWW) at:
http://water.usgs.gov/software/
and via anonymous File Transfer Protocol (FTP) from:
water.usgs.gov (path: /pub/software).
The WWW page and anonymous FTP directory from which the DAFLOW
software can be retrieved are, respectively:
http://water.usgs.gov/software/daflow.html
--and--
/pub/software/surface_water/daflow
SEE ALSO
bltm(1) - Branched Lagrangian Transport Model
branch(1) - One-dimensional Branch-network flow model
wdm(1) - Watershed Data Management system
The URL for this page is: http://water.usgs.gov/cgi-bin/man_wrdapp?daflow
Send questions or comments to h2osoft@usgs.gov