Water Resources Applications Software

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

Summary of BLTM

       bltm - Branched Lagrangian Transport Model

       BLTM uses Lagrangian calculations that are unconditionally stable
       and based upon a reference frame that moves at a velocity equal to
       the mean channel flow velocity.  BLTM results are within the
       accuracy required by most water-quality studies.  The BLTM is easily
       applied to unsteady flows in networks of one-dimensional channels
       with fixed geometry and tributary inflows.  Reaction kinetics for up
       to 10 constituents are provided in a user-written decay-coefficient
       subroutine.  Postprocessor plot programs improve the utility of the
       model.  The model routes any number of interacting constituents
       through a system of one-dimensional channels.

       The following programs are included in the BLTM distribution:

          cbltm   - branched Lagrangian transport model
          qbltm   - bltm with qual2e
          tbltm   - bltm with temperature
          bbltm   - builds the input file for BLTM
          bqual2e - builds the input file for QBLTM
          mrg     - builds a table of data by adding or modifying a
                    column based on data in files old.bc and in,
                    writes file bc
          ctplt   - plots concentration vs time and compute the RMS error
          cxplt   - plots concentration vs distance
          equltmp - computes the equilibrium temperature from daily extreme
          solar   - computes the solar radiation from empirical equations

       The following programs are included in the BLTM distribution and are
       also available as a separate DAFLOW distribution:

          daflow  - diffusion analogy flow model
          wdaflo  - diffusion analogy flow model, uses either flat file or
                    wdm data base
          flwopt  - computes RMS errors to optimize hydraulic coefficients
          bdaflow - builds the input file for DAFLOW
          cel     - computes 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  - estimates ungaged inflow and plot

       The model solves the one-dimensional convective-diffusion equation
       with reaction kinetics.

       The program was developed during the time period 1973-87. This
       distribution was first compiled and given a version number in 1994.

       Version 1.2 1996/11/04 - Several problems were found in the qual2e.f
          code.  Modifications for computing negative flows in computing
          reaeration coefficients were made.  Additionally, there were
          problems related to negative DO; the rate of decay of ammonia and
          nitrite were stopped when the DO approached zero but the
          consumption of DO in the nonexistent transformation continued.
          This has been fixed.

          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

          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.

       1994/08/03 - Changes were made in the bbltm and cbltm programs that
          cause the cbltm input file ( to have a different format.
          The diffusion coefficient is being entered on different records.
          If a file that was created using an earlier version of
          bbltm or cbltm, cbltm will produce results that are in error.

       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

       Flow--areas, top widths, and velocities at each grid point are
       needed for each time step.  Initial conditions--concentration of
       each constituent at each grid at time zero.  Boundary
       conditions--concentration of each constituent at upstream junctions
       and in each tributary during each time step.

       Data are output in text files.  Postprocessor programs are available
       to produce graphical and tabular summaries.

       BLTM and DAFLOW are written in Fortran 77 with the following
       extensions: include files and variable program names longer than 6
       characters.  wdaflow 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. ctplt, cxplt, and flwplt may be implemented
       with a user-supported Computer Associates DISSPLA library or the LIB
       libraries GRAPH, UTIL, and STATS.

       Jobson, H.E., 1997, Enhancements to the Branched Lagrangian
          transport modeling system: U.S. Geological Survey Water-Resources
          Investigations Report 97-4050, 57 p.

       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.

       Schoellhamer, D.H., and Jobson, H.E., 1986, Programmers manual for a
          one-dimensional Lagrangian transport model:  U.S. Geological
          Survey Water-Resources Investigations Report 86-4144, 101 p.

       Schoellhamer, D.H., and Jobson, H.E., 1986, Users manual for a one-
          dimensional Lagrangian transport model:  U.S. Geological Survey
          Water-Resources Investigations Report 86-4145, 95 p.

       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., 1981, Temperature and solute-transport simulation in
          streamflow using a Lagrangian reference frame:  U.S. Geological
          Survey Water-Resources Investigations Report 81-2, 165 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.
       Modeling Flow and Transport in a Riverine Environment (ID2020TC),
       offered annually at the USGS National Training Center.

          U.S. Geological Survey
          Office of Surface Water
          Harvey Jobson
          415 National Center
          Reston, VA 20192

          U.S. Geological Survey
          Hydrologic Analysis Software Support Program
          437 National Center
          Reston, VA 20192

       Official versions of U.S. Geological Survey water-resources analysis
       software are available for electronic retrieval via the World Wide
       Web (WWW) at:


       and via anonymous File Transfer Protocol (FTP) from:

         (path: /pub/software).

       The WWW page and anonymous FTP directory from which the BLTM
       software can be retrieved are, respectively:


       branch(1) - One-dimensional Branch-network flow model
       daflow(1) - Streamflow routing in upland channels or
                   channel networks

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