[GRASS-user] Re: [GRASS-web] raster module for travel time calculations

[Dylan Beaudette]

On Sunday 18 November 2007, Martin Landa wrote:
> Hi,
>
> [Cc: grass-user ML]
>
> 2007/11/18, Kristian Förster <kristian.foerster at googlemail.com>:
> > Dear GRASS developers,
> >
> > I am using GRASS GIS for some hydrological applications. For some
> > questions like flood prediction it is useful to estimate the travel time
> > of surface water in a basin to the outlet. Therefor I've developed a
> > raster program "r.traveltime" which calculates the travel time for each
> > cell in a basin from outputs of r.watershed and r.fill.dir. There is
> > much literature about this procedure available but there's a lag of
> > available software (GRASS and even ArcGIS do not come with such
> > functions). The personal need an the lag of available programs were the
> > reason for me to develop a new program for GRASS GIS. I am not a
> > programming expert, so the program is very simple and far away from
> > being perfect. Maybe if you are interested in these kind of extensions
> > you may list it on your add-on page. Further it could be useful for
> > other users of hydrological applications.
> >
> > r.traveltime is available here:
> > http://home.arcor.de/jesbergwetter/software.html
>

Interesting project summary! It looks like the algorithm is using something 
like the D8 flow routing algorithm, based on the cardinal direction-looking 
artifacts in Fig 4. Do you have a paper or the like detailing the internals? 
Or am I going to have to look at the code :) ?

Thanks for sending the link, a colleague of mine may be able to use this in 
his current research.

Cheers,

Dylan 


-- 
Dylan Beaudette
Soil Resource Laboratory
http://casoilresource.lawr.ucdavis.edu/
University of California at Davis
530.754.7341