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

[Dylan Beaudette]

On Monday 19 November 2007, Dylan Beaudette wrote:
> 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

PS:
for compiling against GRASS 6.3, add the 'grass/' prefix to the two lib 
includes:

#include <grass/gis.h>
#include <grass/glocale.h>

Dylan

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