FUSE

Description and credits

This is a source code repository for the Framework for Understanding Structural Errors or FUSE. FUSE initial implementation is described in the following paper - if you use FUSE, please credit this publication.

• Clark, M. P., Slater, A. G., Rupp, D. E., Woods, R. A., Vrugt, J. A., Gupta, H. V., Wagener, T. and Hay, L. E.: Framework for Understanding Structural Errors (FUSE): A modular framework to diagnose differences between hydrological models, Water Resources Research, 44(12), doi:10.1029/2007WR006735, 2008.

##A. Fork this repository and compile FUSE

1. Fork this repository to a directory $(MASTER) on your machine - the procedure is similar to that described for SUMMA.
2. Change directory to $(MASTER)/build/ and edit the Makefile, by
3. defining the name of the master directory (line 12),
4. defining the path to the NetCDF libraries (lines 162-163),
5. defining the fortran compiler - note that the NetCDF libraries must be compiled using the same compiler that you are using to run the program (line 184).
6. Compile the code (i.e. type make or make -f Makefile).

##B. Define the files to be used

1. In the directory $(MASTER)/bin, edit the file fuse_direktor_08013000.txt to point to the file that defines all of the files required to run FUSE (i.e., change the path to wherever you want to put the file manager file).
2. In the file defined in B1 above (which by default is $(MASTER)/settings/fuse_fileManager.txt), modify the path to define the directories where you would like to keep FUSE settings, FUSE input, and FUSE output. In the example given these directories are simply

• $(MASTER)/settings/
• $(MASTER)/input/
• $(MASTER)/output/

but it may be necessary to store input and output data on a different disk partition that is not backed up (hence, the flexibility). Note that there is also flexibility to change the name of the control files.

##C. Assemble control and input files

1. The file M_DECISIONS (can be called anything, and by default is called fuse_zDecisions.txt) describes the different options available in the FUSE modeling framework. Each of these modeling decisions is described in detail by Clark et al. (WRR, 2008).
2. The file CONSTRAINTS (can be called anything, and by default is called fuse_zConstraints.txt) defines the default parameter values and lower and upper parameter bounds. The list of parameters corresponds to those described in Clark et al. (WRR, 2008). There is alot in this file, mostly used for hierarchacal Bayesian modeling, but the important columns are the default parameter values and lower and upper parameter bounds (everything else is used for research that is still underway).
3. The file MOD_NUMERIX (can be called anything, and by default is called fuse_zNumerix.txt) defines decisions regarding the numerical solution technique. Examples of the impact of these decisions are described by Clark and Kavetski (WRR 2010) and Kavetski and Clark (WRR 2010).
4. The file FORCINGINFO (can be called anything, and by default is called forcinginfo.txt) provides metadata for the model input files. It defines the name of the data file, the number of columns in the data file, the column numbers for precip, potential ET, and runoff, the number of header lines, and the row numbers for the start of the similation, the end of the warm-up period, and the end of the simulation.
5. The model input file resides in the location defined by fuse_fileManager.txt and has the name defined in FORCINGINFO. The only real restriction is that it is an ASCII file. The time step of the forcing data (in days) is defined on the second line of the forcing data file.

##D. Run the puppy Background: different driver programs were written to fulfill different objectives. In each driver program the options are defined through command-line arguments. This facilitates running multiple instances of the executable on a cluster. The filenames are quite long (and descriptive) to avoid different model runs writing to the same file.

Forcing and streamflow data for the catchment USGS 08013000 Calcasieu River near Glenmora, LA are provided as an example in $(MASTER)/input. FUSE can be run using an uniform random sampling of feasible parameter space using the Sobol sequence. The NetCDF output in $(MASTER)/output was created using the following command line argument:

./fuse_URS.exe fuse_direktor_08013000.txt 08013000 070 2 0 1.e-2 1.e-2 1.0000000000 10

where $1 is the muster file, $2 if the ID of the basin, $3 is the ID of the FUSE model, $4 is the method used to temporally integrate model equations (2 is implicit Euler), $5 is a switch between fixed and adaptive sub-steps, $6 is the absolute tolerance for defining the length of sub-steps (adaptive sub-stepping), $7 is the relative tolerance for defining the length of sub-steps (adaptive sub-stepping), $8 is the maximum length of the time step (days) and $9 is the number of random samples desired.

These arguments override the information provided in the control files, specifically:

• $2 is used to define the name of the FORCINGINFO file, and overwrites the information provided in fuse_fileManager.txt.
• $3 is used to define the FUSE model used, and overwrites the information provided in M_DECISIONS (UNLESS the ID is negative, in which case the model decisions are read from the file. The list of model indices is defined in $(MASTER)/settings/fuse_rModelList.txt.
• $4 through $8 overwrites the information provided in the MOD_NUMERIX file.

##E. Plot the results Plot the content of the input and output files, for instance using the code in Sections 1 to 6 of $(MASTER)/r_scripts/plot_fuse_input_output.R. This will make basic consistency tests, e.g. check that the length of the input and output time series and the indices in the settings file are consistent. Since parameter values were obtained from a uniform random sampling, do not expect a good fit of the observed discharge at this stage.

##F. Calibrate FUSE using the shuffled complex evolution method

1. The code of the shuffled complex evolution method (SCE, in file $(MASTER)/build/FUSE_SRC/FUSE_SCE/sce.f, Duan et al., 1992) was written in F77, so it must be compiled separately. We compile it using ifort and the following flags:

ifort -c -fixed -O3 -r8 sce.f  

2. If necessary, rename the compiled file, so that it can be found by $(MASTER)/build/FUSE_SRC/FUSE_SCE/URS_driver_sce.f90, which by default will be looking for a file named sce.o.

3. Adapt and compile $(MASTER)/build/Makefile_sce following the steps A1 to A3.

4. Calibrate FUSE by adapting and executing one following command lines - the second one will take longer to run because of the higher maximum number of trials:

./fuse_URS_sce.exe fuse_direktor_08013000.txt 08013000 070 2 0 1.e-2 1.e-2 1.0000000000 3 50 3 1.e-3
./fuse_URS_sce.exe fuse_direktor_08013000.txt 08013000 070 2 0 1.e-2 1.e-2 1.0000000000 3 5000 3 1.e-3

where $1 to $8 are as above, $9 is the number of calibrated parameter sets desired, $10 is the maximum number of trials before optimization is terminated, $11 is the number of shuffling loops the objective function must change by RC to consider that an optimum has been reached (max=9), $12 is relative change RC.

5. Note that the objective function is RMSE, defined in the file $(MASTER)/build/FUSE_SRC/FUSE_SCE/fuse_rsme.f90 and called by the wrapper $(MASTER)/build/FUSE_SCE/functn.f90.

6. Note that in $(MASTER)/build/FUSE_SRC/FUSE_SCE/URS_driver_sce.f90 the following line turns off the production of time series outputs to save space:

OUTPUT_FLAG = .FALSE.    ! .TRUE. if desire time series output

However, the value of the objective function of each model run is backed up together with parameter values, so that the parameter set associated with the best results can then be run (see Section G below).

##G. Run FUSE with calibrated parameter values

1. Adapt and compile $(MASTER)/build/Makefile_sce_merge following the steps A1 to A3.

2. Create a file containing the name of the NetCDF produced by the SCE calibration (e.g. using $(MASTER)/bin/sce_ncfiles_08013000.txt as template).

3. Run FUSE for the parameter set leading to the lowest RMSE by adapting and executing the following command line:

./fuse_URS_sce_merge.exe fuse_direktor_08013000.txt 08013000 sce_ncfiles_08013000.txt

where $1 is the muster file as above, $2 is the ID of the basin run as above and $3 is the name of the file containing the name of the NetCDF file produced by SCE.

##H. Check the calibration results Explore the calibrated parameter values and plot the calibrated model runs, e.g. using the code in Sections 7 and 8 of $(MASTER)/r_scripts/plot_fuse_input_output.R. This will plot the evolution of the NSE through the calibration and check that the NSE values returned by SCE are consistent with those computed in R using the observed discharge from the input file and the simulated discharge from the output file.

License

FUSE is distributed under the GNU Public License Version 3. For details see the file LICENSE in the FUSE root directory or visit the online version.