NAME
bltm - Branched Lagrangian Transport Model
ABSTRACT
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
temperatures
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
METHOD
The model solves the one-dimensional convective-diffusion equation
with reaction kinetics.
HISTORY
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
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.
1994/08/03 - Changes were made in the bbltm and cbltm programs that
cause the cbltm input file (bltm.in) to have a different format.
The diffusion coefficient is being entered on different records.
If a bltm.in 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
series.
DATA REQUIREMENTS
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.
OUTPUT OPTIONS
Data are output in text files. Postprocessor programs are available
to produce graphical and tabular summaries.
SYSTEM REQUIREMENTS
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.
DOCUMENTATION
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.
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., 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.
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 BLTM
software can be retrieved are, respectively:
http://water.usgs.gov/software/bltm.html
--and--
/pub/software/water_quality/bltm
SEE ALSO
branch(1) - One-dimensional Branch-network flow model
daflow(1) - Streamflow routing in upland channels or
channel networks