output: Gradient Sinuosity stream reach length down valley distance This is a thought- and I have no idea how to implement it. I would like to calculate thalweg distance of a stream. from the start point (user input) search xmeters to the east and west find the minimum - move one grid cell south and search x meters east and west find the minimum. find the elevation difference between point 1 and 2. then use the Pythagorean theorem to calculate the distance. Iterate to the termination point (user input). add all of the lengths up. calculate the distance between the start and end, elevation difference. You would then get slope (gradient) of the stream segment, total thalweg distance, and total distance down the valley. total thalweg distance/total distance down the valley is sinuosity. Is this possible? Is there a way to only search within the stream segment generated by r.watershed or r.stream extract or... I will help in any way that I can- I just don't know how to do this. kindest regards,
Stephen On Fri, Jul 9, 2010 at 9:59 AM, Mark Seibel <[email protected]> wrote: > I came across this when looking previously at v.to.db. I noticed there > is an option to upload line sinuosity. I haven't tried it, but I'd be > curious to know if it solves your problem. > > Using "option = sinuous" ? > > http://grass.itc.it/grass64/manuals/html64_user/v.to.db.html > > Mark > > On Fri, Jul 9, 2010 at 10:24 AM, stephen sefick <[email protected]> wrote: >> All: >> I would like to calculate channel sinuosity on many streams that I >> have an upstream and downstream GPS point. Is there such a module in >> GRASS? I am trying to avoid doing this by hand. >> kindest regards, >> >> -- >> Stephen Sefick >> ____________________________________ >> | Auburn University | >> | Department of Biological Sciences | >> | 331 Funchess Hall | >> | Auburn, Alabama | >> | 36849 | >> |___________________________________| >> | [email protected] | >> | http://www.auburn.edu/~sas0025 | >> |___________________________________| >> >> Let's not spend our time and resources thinking about things that are >> so little or so large that all they really do for us is puff us up and >> make us feel like gods. We are mammals, and have not exhausted the >> annoying little problems of being mammals. >> >> -K. Mullis >> _______________________________________________ >> grass-user mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/grass-user >> > -- Stephen Sefick ____________________________________ | Auburn University | | Department of Biological Sciences | | 331 Funchess Hall | | Auburn, Alabama | | 36849 | |___________________________________| | [email protected] | | http://www.auburn.edu/~sas0025 | |___________________________________| Let's not spend our time and resources thinking about things that are so little or so large that all they really do for us is puff us up and make us feel like gods. We are mammals, and have not exhausted the annoying little problems of being mammals. -K. Mullis _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
