[GRASSLIST:10014] Re: Filling with flood

[Māris Nartišs]

Hi,

1) as it is my first piece of C code, could somebody look on it. Any
suggestions = welcome;

2) specifying seed as x,y pair is in my planed feature list. Still
possibility to use raster map as seed is important, cuz seed must be
at least one cell with value>0, so it can be already existing lake
map, also output from previous module runs. It is possible to create
cool anime with water level falling :)

3) next week I will have to present this module at local conference[1]
and I will need some cool presentation stuff. Thanks for idea about
flooding city in 3D. If I will manage to create such anime, I will
give it for putting on GRASS site.

4) before adding this module to CVS, I want to i) add blue gradient to
output map (see commented code at end of module source); ii) add
ability to set seed as x,y. As now seems that ice age is over, I will
be able to work at home to add those features (last week air
temperature at my room was about +10C, cuz outside temperature was
below -30C).


tnx for ideas, interest,
Maris.

[1] http://www.lu.lv/petnieciba/konferences/lu64/ (in Latvian) ~=
"University of Latvia 64. scientific conference"

2006/1/26, Hamish <hamish_nospam at yahoo.com>:
> Wow, lots of good ideas.
>
>
> > Creating dam:
> > 1) With r.digit digitise map dam line; Assign correct height to it;
> > 2) Grow it to 2 cells atleast to avoid any holes in dam;
> > 3) With r.mapcalc add dam to DEM.
> >
> > Filling lake:
> > 1) With r.digit create map with atleast one cell with any value below
> > target water level (seed);
> > 2) Feed in DEM, seed, target water level to r.lake.
>
> Could the seed be part of the module? seed_location=x,y seed_elevation=z
> Could save some effort, the less work that needs to be done by hand the
> better / faster.
>
>
> Another question.. how to model sea level rise / storm surge?
> v.in.region to get an outside box -> v.to.rast -> r.lake?
>
> e.g. combine with images like this by Markus + Jachym's v.extrude:
> http://mpa.itc.it/markus/grass61/demos/
>
> and you have *incredibly* effective graphics to show to planners,
> public, etc. Make an animation of the flooding happening in NVIZ,
> even more so. e.g. do for Downtown New Orleans.. as most major world
> cities are harbour-front, there is much demand and modelling already
> happening around this.
>
> In the past I have used a trick in NVIZ with a second, semi-transparent,
> constant surface and raised & lowered the z-offset*, but that is really
> visualization only qualitative approach.
>
> [*] http://bambi.otago.ac.nz/hamish/pics/sill_iceage_115m.jpg
>
> River flooding is more difficult I guess as the surface is not at a
> constant elevation, but it would be nice to transfer watershed volume
> accumulations to a flood which rose until volume was exhausted?
>
>
>
> Hamish
>