Add setup function for zsini file

[couasnonanais]

It might be a good idea to add a setup_ function to also generate the zsini file in cases where a constant water level is not "appropriate".
I know a few users that have run into this request.

[DirkEilander]

Thanks for this suggestion. Based on what data could we create this ini file? Note that we can already dynamically create such file by setting restartfile = sfincs.restart in the sfincs.inp file.

[couasnonanais]

Indeed, that could be one argument of this function in case where a sfincs.restart file exist. Otherwise, it could be a combination of a mask (like a water mask or river mask or both) that indicates where the initial water elevation is higher and the additional water depth. This would be, for example, useful in very steep catchment so that the run doesn't start "dry".

[hcwinsemius]

Perhaps a scaled factor of the topographic index could work. Then you ensure that areas with large upstream areas and/or low slopes get a thicker layer of water than small upstream areas with large slopes.

[Leynse]

Could to something like this in a setup_ function:

AD365 = xr.open_dataarray(r'0365AD_Shaw_2008_initial_waterlevel.tif')
AD365 = AD365.raster.mask_nodata(fill_value=0)
AD365 = AD365.raster.reproject_like(sf.mask)

sname = "zsini"
AD365.attrs.update(**sf._ATTRS.get(sname, {}))

sf.set_states(AD365, name=sname)

And have some options like the ones you suggest in earlier comments

[nmertzanis]

@DirkEilander I believe the restartfile is not currently working. There is no code to actually parse the file even if it is set. Moreover, manually setting the zsini values to be variable over the map causes some bugs which I believe are urgent to address. After all, without the ability to restart from a previous state the possible uses are limited.

[couasnonanais]

Hi @nmertzanis,

I am not sure whether your post applies to this issue. Are you using hydromt-sfincs to update a model? After reading your message, it seems more like a problem in SFINCS itself? In that case I would put an issue on the SFINCS repo.
You can find more information on how to use of a restart file here: https://sfincs.readthedocs.io/en/latest/input.html#restart-file