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Water Resources Applications Software

Geochemical || Ground Water || Surface Water || Water Quality || General

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

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Send questions or comments to h2osoft@usgs.gov