Ideas for new major features of BG_Flood

[CyprienBosserelle]

What major feature to prioritise for v2.XX

BG_Flood is a model for simulating flood hazard from various and possibly compounded source. Think of a storm surge and a river flood together where instead of explicitly forcing the tide boundary close to the river you simulate the storm surge generation from wind and atmospheric pressure on a reginal scale but with a high resolution where the river is flowing. BG_Flood is designed to be good at that.

We're trying to figure out what other features are critical to make BG_Flood even more relevant.

Note
Please give your input below

Things that are already flagged

A few key feature to us are missing from BG_Flood will be added in the model although some of these features may be reduced or dropped if they become too hard. I already started a discussion about waves here: #76

• A way to include waves (XBeach_Style)
• Flood structures: bridges, (short) culverts, walls
• On-the-fly adaptation of the mesh
• Non-dispersive solver for tsunamis (likely the non-hydrostatic solver from Basilisk)

Things that we know should be great

Groundwater flooding

Groundwater flooding is a big process that BG_Flood cannot resolve at the moment but equation for GW flow are relatively simple to implement and there are great open-source code we can get some inspiration.
This could be linked to the initial and continuing loss model in place to maintain the injected mass. However there are some fundamental questions about how you initialize a GW model.

Storm water system

A lot of work on inundation inherently happens in urban environment so ignoring storm water system is really not a very long term solution for the code. This is not trivial but could be done with culverts and do 2 birds in one stone.

Sediment transport and morphological changes

Is this a priority?. While it would be nice it is a major undertaking and would probably need to be spanned between 2 major releases.

Density driven flow

At the moment BG_Flood ignores density difference between fresh and saltwater. The goal is not to make another regional ocean model but to simulate the kind of things that happens in river mouth and estuaries. This would not be too hard with the hydrodstatic version of the most recent Basilsik software likely needed for v2.0 so some progress in that direction could easily be the focus of V2.0.

Better handling of GIS input-output

I think this is critical.

• SHP files as input
• Geotif input and output
• OGR - GDAL handling

More "onboard" post-processing of the results

• collapse of all the level into a single output
• Transect integrated output ?

Faster , faster, faster...

Fry wants to go faster

Adaptive time step.

Using different time step for different block levels. The model uses the smallest time step across all the blocks at the moment. The smallest time step is very likely to be the time step required by the highest level (in the deepest water). that means that the lower level could potentially run at time step that are twice as long.
e.g. level 2 runs 2 steps at dt=1s but level 1 only runs 1 step at dt=2s.

MPI version of CPU code

yes we probably should have had that in v1.0...

More tutorial/example training docs

We do need to put more documentation.

Frontend

An Html frontend would be easy to implement.