[GRASS-user] Channel Sinuosity Implemented in GRASS?

[stephen sefick]

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 <mseibel at gmail.com> 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 <ssefick at gmail.com> 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                                                    |
>> |___________________________________|
>> | sas0025 at auburn.edu                             |
>> | 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
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>>
>



-- 
Stephen Sefick
____________________________________
| Auburn University                                   |
| Department of Biological Sciences           |
| 331 Funchess Hall                                  |
| Auburn, Alabama                                   |
| 36849                                                    |
|___________________________________|
| sas0025 at auburn.edu                             |
| 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