[GRASS-user] Trento3D screenshots redone

[Thomas Adams]

Paulo,

You're right about the need for modeling. Actually, the modeling would 
be done outside of GRASS and then have the appropriate water surface 
elevation data imported into GRASS to show the inundated areas. The 
hydraulic modeling *could* be done withing GRASS, but a better first 
step probably would be to do the modeling outside of GRASS and then 
import the data. An additional advantage to this is that there are many 
hydraulic models and one may have a preference as to which to use or, 
not be restricted to a particular model, thereby retaining more flexibility.

Tom


pmarc wrote:
> 2006/5/19, Thomas Adams <Thomas.Adams at noaa.gov>:
>> Hamish & Markus,
>>
>> How did you do the inundation? With r.lake; does this use a level
>> surface? If so, this is not correct for a river, due to the downstream
>> slope of the topography and the hydrodynamics of the flow. The resulting
>> water surface elevations would be less than a level surface. Channel &
>> overbank cross-sections are needed (corresponding to those used in a
>> dynamic flow model) which then need to be intersected with the
>> topography. The US Army Corps of Engineers HEC-RAS & HEC-GeoRAS software
>> that is integrated with ArcGIS does this correctly.
>
> Well, that was just to showcase possibilities and then you come with a
> class on hidrology!!
>
> Thanks!
>
> I think it should be easy to add a slope to that flood surface, but
> that would be still incorrect.
> The solution would be to implement a flood modelling routine, but
> then, this is the beauty of free software! However, with all my
> excitement about all this, I am not the person to implement it... I'm
> still lacking some work on the localization of GRASS....
>
> I think I speak for the whole community when I say we are glad to see
> GRASS being used is such hi-profile tasks.


-- 
Thomas E Adams
National Weather Service
Ohio River Forecast Center
1901 South State Route 134
Wilmington, OH 45177

EMAIL:	thomas.adams at noaa.gov

VOICE:	937-383-0528
FAX:	937-383-0033