Re: [Anuga-user] Fwd: Can we speed up a bit second and on model runs?

[<jlu...@sa...>]

Ole

Let's say that I understand what you are talking about but still have =20
some difficulties with the implementation.

> I am assuming that this is similar to the flows we had earlier where =20
> stage and elevation were almost but not exactly identical in that =20
> particular area.

So it seams but on another context.

> Smoothing will change the elevation surface slightly and may thus =20
> lead to z being less than w in different parts if it was close to =20
> begin with.
>
> Have a look at the values for elevation and check if they are less =20
> than your initial w which I think is 0.0 in this case.
>
> I suggest setting stage initially to be well below the elevation =20
> surface if you want to ensure the initial condition is 'dry'. ANUGA =20
> will bring it up to the elevation anyway.

I'm running the example where stage =3D elevation on land. However, this =20
is the case with the coarse (800 meters) boundary condition file - the =20
sww file. I have no idea of the internals but at the first slice (t =3D =20
0) we already have a stage-almost-equal-to-elevation at the resolution =20
of the fine grid. So whatever the process that assigns stage to ALL =20
nodes of the fine grid is, shouldn't it take care that =20
stage-is-equal-to-elevation on 'dry'? Than I would understand the =20
effect of the alpha smoothing in producing spurious lakes on very low =20
lands but what we see is that the lake creation effect is larger in =20
the without smoothing (no alpha) condition.

> The criterion is w > z (stage > elevation).
I'm using abs((w - z) > 1e-7)

> We have implemented some routines that will detect maximal run-up =20
> height based on this criterion. This finds the heighest elevation =20
> point that got wet. See =20
> http://datamining.anu.edu.au/~ole/anuga/user_manual/anuga_user_manual.pdf
> page 53 where the functions get_maximum_inundation_elevation and =20
> get_maximum_inundation_location are described.

I have equivalents in "Aquamoto". Unfortunately I just found a bug in =20
the version of which I posted the file locations before. In order that =20
the button with "Plot Run In" works, the user has to kill the Mirone =20
window before using it. No problem, it will be recreated by pushing =20
that button.
To get the run up one must use a trick. Once you have the polygon =20
defining the run in zone, right click on it and select "ROI Crop Tools =20
-> Crop Grid". The extracted grid will have valuable data only inside =20
the polygon, so its maximum is by definition the run up.

Cheers
Joaquim