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Using the models

Directory structure: cases and runs

A case is a directory holding all the data needed to run the model. Multiple cases may exist next to each other in separate directories. The model will only work with one case at the time. If no case is specified when starting the model a default case (default_sbm or default_hbv) is assumed. Within a case the model output (the results) are stored in a separate directory. This directory is called the run, indicated with a runId. This structure is indicated in the figure below:

digraph file_system {
//rankdir=LR;
size="8,11";
"Case" -> "inmaps";
"Case" -> "instate";
"Case" -> "intbl";
"Case" -> "intss";
"Case" -> "outstate";
"Case" -> "Run";
"Case" -> "staticmaps";
   "Run" -> " intbl";
   "Run" -> "outmaps";
   "Run" -> " outstate";
   "Run" -> "outsum";
   "Run" -> "runinfo";
}

If you want to save the results and not overwrite the results from a previous run a new runId must be specified.

inmaps
Directory holding the dynamic input data. Maps of Precipitation, potential evapotranspiration and (optionally) temperature in pcraster mapstack format.
instate
Directory holding the input initial conditions. Can be used to hotstart the model. Alternatively the model can start with default initial conditions but in that case a long spinup procedure may be needed. This is done using the -I command-line option.
intbl
Directory holding the lookup tables. These hold the model parameters specified per landuse/soiltype class. Note that you can use the -i option to specify an alternative name (e.g. to support an alternative model calibration). Optionally a .tbl.mult file can be given for each parameter. This file is used after loading the .tbl file or .map file to multiply the results with. Can be used for calibration etc.
intss
Directory holding the scalar input timeseries. Scalar input data is only assumed if the ScalarInput entry in the ini file is set to 1 (True).
outstate
Directory holding the stat variable at the end of the run. These can be copied back to the instate directory to have the model start from these conditions. These are also saves in the runId/outstate directory
run_default
The default name for a run. if no runId is given all output data is saved in this directory.
staticmaps
Static maps (DEM, etc) as prepared by the wflow_prep script.
wflow_sbm|hbv.ini
The default settings file for wflow_sbm of wflow_hbv

Running the model

Overview

In general the model is run from the dos/windows/linux command line. Based on the system settings you can call the wFlow_[sbm|hbv].py file directly or you need to call python with the script as the first argument e.g.:

python wflow_sbm.py -C myCase -R calib_run -T 365 -f

In the example above the wflow_sbm model is run using the information in case myCase storing the results in runId calib_run. A total to 365 timesteps is performed and the the model will overwrite existing output in the calib_run directory. The default .ini file wflow_sbm.ini located in the myCase directory is read at startup.

Command-line options

The command line options for wflow are summarized below, use wflow -h to view them at the command line:

wflow_sbm [-h][-v level][-F runinfofile][-L logfile][-C casename][-R runId]
      [-c configfile][-T last_step][-S first_step][-s seconds][-W][-E][-N][-U discharge]
      [-P parameter multiplication][-X][-f][-I][-i tbl_dir][-x subcatchId][-u updatecols]
      [-p inputparameter multiplication]
-F: if set wflow is expected to be run by FEWS. It will determine
    the timesteps from the runinfo.xml file and save the output initial
    conditions to an alternate location. The runinfo.xml file should be located
    in the inmaps directory of the case.
-X: save state at the end of the run over the initial conditions at the start
-f: Force overwrite of existing results
-T: Set last timestep
-S: Set the start timestep (default = 1)
-N: No lateral flow, use runoff response function to generate fast runoff
-s: Set the model timesteps in seconds
-I: re-initialize the initial model conditions with default
-i: Set input table directory (default is intbl)
-x: run for subcatchment only (e.g. -x 1)
-C: set the name  of the case (directory) to run
-R: set the name runId within the current case
-L: set the logfile
-E: Switch on reinfiltration of overland flow
-c: name of wflow the configuration file (default: Cassename/wflow_sbm.ini).
-h: print usage information
-W: If set, this flag indicates that an ldd is created for the water level
    for each timestep. If not the water is assumed to flow according to the
    DEM. Wflow will run a lot slower with this option. Most of the time
    (shallow soil, steep topography) you do not need this option. Also, if you
    need it you migth actually need another model.
-U: The argument to this option should be a .tss file with measured discharge in
    [m^3/s] which the program will use to update the internal state to match
    the measured flow. The number of columns in this file should match the
    number of gauges.
-u: list of gauges/columns to use in update. Format:
    -u [1 , 4 ,13]
    The above example uses column 1, 4 and 13
    Note that this also sets the order in which the updating takes place! In
    general specify downstream gauges first.
-P: set parameter multiply dictionary (e.g: -P 'self.FirstZoneDepth' : 1.2
    to increase self.FirstZoneDepth by 20\%, multiply with 1.2)
-p: set input parameter (dynamic, e.g. precip) multiply dictionary
    (e.g: -p 'Precipitation' : 1.2 to increase Precipitation
    by 20%, multiply with 1.2)
-v: set verbosity level

wflow_sbm|hbv.ini file

The wflow_sbm|hbv.ini file holds a number of settings that determine how the model is operated. The files consists of sections that hold entries. A section is define using a keyword in square brackets (e.g. [model]). Variables can be set in each section using a keyword = value combination (e.g. ScalarInput = 1). The default settings for the ini file are given in the subsections below.

[model] Options for all models:

ModelSnow=0
Set to 1 to model snow using a simple degree day model (in that case temperature data is needed)
ScalarInput=0
If set to 0 input maps are needed for each timestep in the inpumaps directory., If set to 1 the model will use input timeseries from the inputtss directory and interpolate these to maps at run-time.
InterpolationMethod=pol
Interpolation method when using scalar timeseries input. The method can be pol (Thiessen polygons) or inv (Inverse Distance). The same method is used for all parameters (P. PET, T).
WIMaxScale=0.8
Scaling for the topographical wetness vs soil depth method
Tslice=1
Number of timeslices per timestep used in the kinematic wave formula
UpdMaxDist=10000.0
Maximum distance from the gauge to apply updating to. Only used if you force the model with measured discharge
fewsrun=0
Indicates the model is running from Delft-FEWS or not

Specific options for wflow_sbm :

RunoffGenSigmaFunction = 0
Use subcell runoff generation based on fitting a Sigmoid function to percentile Dems. (wflow_sbm only)
reinit = 0
If set to 1 (one) the model will not read the saved initial state files from the instates directory but start with cold states.
OverWriteInit = 0
If set to one the initial states will be overwritten
updating = 0
Set to 1 to switch on Q updating.
updateFile
If updating is set to 1 specify a
sCatch = 0
If set to another value than 0 the model will only use the specified subcatchment
intbl = intbl
directory from which to read the lookup tables (relative to the case directory)
timestepsecs = 86400
timestep of the model in seconds
Alpha = 60
Alpha term in the river width estimation function
AnnualDischarge = 300
Average annual discharge at the outlet of the catchment for the river wiidth estimation function.
UpdMaxDist = 100
Maximum distance from the gauge used in updating for which to update the kinematic wave reservoir (in model units, metres or degree lat lon)
waterdem = 0
if set to 1 the ldd will be recalculated each timestep based on the DEM + the water level
reInfilt = 0
If set to 1 water from the kinamatic wave reservoir can reinfiltrate in the soil

The options below should normally not be needed. Here you can change the location of some of the input maps.

wflow_subcatch=staticmaps/wflow_subcatch.map
map with the subcatchments
wflow_dem=staticmaps/wflow_dem.map
the digital elevation map
wflow_ldd=staticmaps/wflow_ldd.map
the local drainage network
wflow_river=staticmaps/wflow_river.map
all the cells marked as river
wflow_riverlength=staticmaps/wflow_riverlength.map
the length of the ‘river’ in each cell
wflow_riverlength_fact=staticmaps/wflow_riverlength_fact.map
factor to multiply the river length with
wflow_landuse=staticmaps/wflow_landuse.map
landuse map
wflow_soil=staticmaps/wflow_soil.map
soil map
wflow_gauges=staticmaps/wflow_gauges.map
map with the gauge locations
wflow_inflow=staticmaps/wflow_inflow.map
map with forced inflow points (optional)
wflow_mgauges=staticmaps/wflow_mgauges.map
map with locations of the meteorological gauges (only needed if you use scalar timeseries as input)
wflow_riverwidth=staticmaps/wflow_riverwidth.map
map with the width of the river

[defaultfortbl]

RunoffGeneratingGWPerc = 0.1
Default value for the upper fraction of the groundwater reservoir that generates runoff (wflow_sbm only)

[layout]

sizeinmetres = 0
If set to zero the cell-size is given in lat/long (the default), otherwise the size is assumed to be in metres.

[outputmaps]

Outputmaps to save per timestep. Valid options for the keys in the wFlow_sbm model are all variables visible the dynamic section of the model (see the code). A few useful variables are listed below.

[outputmaps]
self.Runoff=run
self.SnowMelt=sno
self.FirstZoneFlux=fzf
self.FirstZoneDepth=fir

Tip

NB See the wflow.py code for all the available variables as this list is incomplete.

The values on the right side of the equal sign can be choosen freely.

Example content:

Self.Runoff=run
self.FirstZoneFlux=fzf
self.FirstZoneDepth=fir

[outputcsv_0-n] [outputtss_0-n]

Number of sections to define output timeseries in csv format. Each section should at lears contain one samplemap item and one or more variables to save. The samplemap is the map that determines how the timesries are averaged/sampled. All other items are variabale filename pairs. The filename is given relative to the case directory.

Example:

[outputcsv_0]
samplemap=staticmaps/wflow_subcatch.map
self.SurfaceRunoffMM=Qsubcatch_avg.csv

[outputcsv_1]
samplemap=staticmaps/wflow_gauges.map
self.SurfaceRunoffMM=Qgauge.csv
self.WaterLevel=Hgauge.csv

[outputtss_0]
samplemap=staticmaps/wflow_landuse.map
self.SurfaceRunoffMM=Qlu.tss

In the above example the discharge of this model (self.SurfaceRunoffMM) is saved as an average per subcatchment, a sample at the gauge locations and as an average per landuse.

[inputmapstacks]

This section can be used to overwrite the default names of the input mapstacks

Precipitation = /inmaps/P
timeseries for rainfall
EvapoTranspiration = /inmaps/PET
potential evapotranspiration
Temperature = /inmaps/TEMP
temperature time series
Inflow = /inmaps/IF
in/outflow locations (abstractions)

Updating using measured data

Note

Updating is only supported in the wflow_sbm and wflow_hbv models.

If a file (in .tss format) with measured discharge is specified using the -U command-line option the model will try to update (match) the flow at the outlet to the measured discharge. In that case the -u option should also be specified to indicate which of the columns must be used. When updating is switched on the following steps are taken:

  • the difference at the outlet between measured and simulated Q (in mm) is determined
  • this difference is added to the unsaturated store for all cells
  • the ratio of measured Q divided by simulated Q at the outlet is used to multiply the kinematic wave store with. This ratio is scaled according to a maximum distance from the gauge.

Please note the following points when using updating:

  • The tss file should have as many columns as there are gauges defined in the model
  • The tss file should have enough data points to cover the simulation time
  • The -U options should be used to specify which columns to actually use and in which order to use them. For example: -u ‘[1,3,2]’ indicates to use column 1,2 and 3 in that order.

All possible options in wflow_sbm.ini file

[defaultfortbl]
RunoffGeneratingGWPerc = 0.1

[layout]
sizeinmetres = 1

[fit]
areamap = staticmaps/wflow_subcatch.map
areacode = 1
Q = testing.tss
WarmUpSteps = 1
ColMeas = 0
parameter_1 = RootingDepth
parameter_0 = M
ColSim = 0

[misc]

[outputmaps]
self.SurfaceRunoff = run

[framework]
debug = 0
outputformat = 1

[inputmapstacks]
Inflow = /inmaps/IF
Precipitation = /inmaps/P
Temperature = /inmaps/TEMP
EvapoTranspiration = /inmaps/PET

[model]
wflow_river = staticmaps/wflow_river.map
InterpolationMethod = inv
reinit = 1
WIMaxScale = 0.6
wflow_riverlength_fact = staticmaps/wflow_riverlength_fact.map
OverWriteInit = 0
intbl = intbl
wflow_riverwidth = staticmaps/wflow_riverwidth.map
wflow_soil = staticmaps/wflow_soil.map
ExternalQbase = 0
updateFile = no_set
sCatch = 0
Alpha = 120
UpdMaxDist = 300000.0
wflow_subcatch = staticmaps/wflow_subcatch.map
wflow_mgauges = staticmaps/wflow_mgauges.map
timestepsecs = 86400
RunoffGeneratingGWPerc = 1.0
RunoffGenSigmaFunction = 1
ScalarInput = 0
reInfilt = 0
fewsrun = 0
wflow_dem = staticmaps/wflow_dem.map
ModelSnow = 0
AnnualDischarge = 2290
wflow_landuse = staticmaps/wflow_landuse.map
updating = 0
TemperatureCorrectionMap = staticmaps/wflow_tempcor.map
wflow_inflow = staticmaps/wflow_inflow.map
wflow_riverlength = staticmaps/wflow_riverlength.map
wflow_ldd = staticmaps/wflow_ldd.map
wflow_gauges = staticmaps/wflow_gauges.map
Tslice = 1
waterdem = 0