Frequently asked questions#

This page contains some FAQ / tips and tricks to work with HydroMT-Wflow. For more general questions on how to work with data or the HydroMT config and command line, you can visit the HydroMT core FAQ page

Building a Wflow model#

Q: Can I use other region arguments that basin or subbasin ?

To build a Wflow model, it is strongly recommended to use the basin or subbasin when defining your region of interest. This ensures that all upstream contributing cells are well taken into account. Using other options might cause your Wflow model run crash. If you are sure of what you are doing, you can optionnaly use the geom option and provide an exact shapefile of the basin/subbasins you want to derive, that was prepared using the same DEM source that you intend to use in the setup_basemaps() method.

Q: Can I derive several sub-basins at the same time using a bounding box or a geometry instead of a list of point corrdinates?

To derive subbasin with HydroMT, you also need to provide in your region options a snapping arguments so that HydroMT knows what type of subbasin you want to create. You can use either streamorder strord or upstream area uparea type of snapping:

  • “{‘subbasin’: [xmin, ymin, xmax, ymax], ‘strord’: 3}”

  • “{‘subbasin’: ‘path/to/geomtry.shp’, ‘uparea’: 100000}”

Q: Can I use a different dataset for precipitation and temperature forcing data?

Yes, that is one of the reason why the two were separated into two separate methods: setup_precip_forcing() and setup_temp_pet_forcing(), you can just use a different data source for precip_fn and temp_pet_fn and HydroMT will do its resampling magic!

Q: Can I add several gauges at the same time ?

Sure! HydroMT allows you to use several times the same method in your configuration file. For this, you just need to start enumerating the methods by adding a number to the end of the method name. For example:

[setup_gauges]
gauges_fn = my_gauges1

[setup_gauges2]
gauges_fn = my_gauges2
derive_outlets = False # To avoid deriving basin outlets twice

Updating a Wflow model#

Q: Is there an easy way to update reservoirs or lakes parameters in my Wflow model ?

To easily update reservoirs or lakes parameters, you can directly use the reservoirs.geojson and lakes.geojson that are saved by HydroMT into the staticgeoms folder. Once you have updated the parameters with the new value, just use these geojson files as your new “local” input data!

Q: Can I select a specific Wflow TOML config file when updating my model ?

It is possible. In that case, you need to start your HydroMT configuration with a read_config() method where you can specify which TOML file to use using the config_fn argument.

Others#

Q: Can I convert my old Wflow python model to the new Wflow Julia version with HydroMT ?

HydroMT is still able to read the python PCRaster based maps of Wflow with the method read_staticmaps_pcr(). So actually just a read and write of your python model will do most of the job :) The intbl are however not taken into account so if you have single values intbl, you can use the setup_constant_pars() method. For lakes and reservoirs parameters, the best is to use a shapefile of yours lakes and reservoirs with the right columns for each parameters (see previous question on updating reservoir).