A Random Walk Particle Tracking Code for Solute Transport in Heterogeneous Aquifers
MODPATH-RW is a Random Walk Particle Tracking (RWPT) model, implemented by extension of the particle tracking program MODPATH-v7. The code employs discrete solute particles to solve the Advection Dispersion Equation (ADE), and inherits the parallel processing of particles from MODPATH-OMP.
The program is naturally integrated with groundwater flow models obtained with MODFLOW-2005, MODFLOW-USG and MODFLOW 6, for structured and rectangular unstructured grids.
Clone the repository
git clone https://github.com/upc-ghs/modpath-rw
Some external dependencies are stored in the src/lib folder. The necessary files are all explicitly included in the repository for convenience.
-
gpkde: module for smoothed reconstruction of concentrations. -
finterp: module for linear interpolation. -
rng_par_zig: module for random number generation in parallel with the Ziggurat method.
Makefiles are available at the folder make:
makefile-gfortran-pc: for thegfortrancompiler.makefile-ifort-pc: for theifortcompiler, verified forifort@2021.9.0.makefile-gfortran-mac: for thegfortrancompiler in macOS.makefile-gfortran-wos: for thegfortrancompiler in Windows (tested with mingw-w64).
By default, the compiled program is called mpathrw. Compilation process will create a folder with temporary objects (make/objtemp). When integrating program updates and recompiling, it is advised to remove this folder to avoid inconsistencies.
The program can be built with the meson build system:
- Setup the configuration:
meson setup builddir -Ddebug=false --prefix=$(pwd) --libdir=bin
- Compile:
meson install -C builddir
- Test:
meson test --verbose --no-rebuild -C builddir
A Windows executable is available at the folder wbin/. The latest version of the Windows executable is built with mingw-w64 gfortran, with static linking of libraries, meaning that the executable bundles all the necessary Fortran libraries (e.g., OpenMP).
Note: This new Windows executable replaces the former executable generated with the Intel compiler and Visual Studio, which will remain as legacy updated until commit e216a4d (see below).
The folder msvs contains the project and solution files generated with Visual Studio 2022 on a Windows system. An executable file and complementary dll's providing the OpenMP library are available at the folder wbin/. Users can make easy use of these files at a system level by extending the PATH environment variable, adding their specific address to the wbin/ folder (as here or here).
The necessary dll's can also be installed from the Intel and Visual Studio redistributables (x64), respectively:
Note: The Windows executable generated with the Intel compiler and Visual Studio will remain as legacy, updated until commit e216a4d.
Details about the configuration of input files are provided in the program Documentation of Input-Output. It is recommended to follow this document closely with the Description of Model Input and Output of MODPATH-v7.
Users familiarized with the python interface FloPy are encouraged to write input files for MODPATH-RW with the extension flopyrw. This package provides classes based on the interface for mp7, which have been adapted to the specific requirements of MODPATH-RW, plus new classes for the new model packages. The extension is consistent with the program documentation and example configuration routines and test cases can be found on the project page.
A command line interface provides some simple instructions and shortcuts for managing program execution. Asking for help (mpathrw -h) displays the following message
MODPATH-RW version *.*.*
Program compiled MMM DD YYYY HH:MM:SS with ******** compiler (ver. *******)
A Random Walk Particle Tracking code for solute transport in heterogeneous aquifers
usage:
mpathrw [options] simfile
options:
-h --help Show this message
-i --init Initialize simulation without running
-l <str> --logname <str> Write program logs to <str>
-nl --nolog Do not write log file
-np <int> --nprocs <int> Run with <int> processes
-p --parallel Run in parallel
-ts <int> --tsoutput <int> Selects timeseries output <int>
-s --shortlog Simplified logs
-v --version Show program version
For bug reports and updates, follow:
https://github.com/upc-ghs/modpath-rw
Note: if the OpenMP library is not found by compilers, the program will be generated without parallel compatibility, without the input parameters nprocs, parallel and tsoutput. If these are listed on the program help message (as above), the compilation with parallel compatibility was successful.
--init: initialize the program packages and stop execution before displacing particles. Useful to monitor the initialization workflow and reports written to the mplst file.
--nprocs: run in parallel with the given number of processes (omp_set_num_threads(nprocs)).
--parallel: shorthand for running in parallel with the maximum number of processors (omp_get_num_procs()).
Note: if neither --parallel nor --nprocs are given, the program will by default employ omp_get_max_threads(), whose value can be controlled with the environment variable OMP_NUM_THREADS.
--tsoutput: controls the output protocol for timeseries runs while running in parallel
- 1: is the default format, output is performed into a single output unit with the OpenMP thread exclusive clause (critical). Only difference versus a serial run is that the output file contains non-sorted particle indexes.
- 2: timeseries records are written into thread specific binary units and then consolidated into a single file after each timeseries output time. Timeseries file generated with this format does not contains a file header.
- 3: timeseries records are written into thread specific output units. Timeseries file header is written only to the output unit of the first thread
1_example.timeseries. Initial particle positions are also written to the file of the first thread.
Follow the contribution guidelines for this project.
MIT License