[GRASS-user] Cut a floodplain polygon with 1meter wide polygons perpendicular to its river channel

[Shane Carey]

Ok, I seem to be getting closer to what I need. It works well where the
river is perpendicular to the column (see slide 3) but where it is
parrallel (see slide 4), I would need to obtain a rows map. Is there any
way of being able to tell it to create rows or columns based on the river
direction?

<goog_326768947>
https://docs.google.com/presentation/d/1x7IQ3BJlLLSb6R2atxIIiaeWzyCqCZQ3uWaGPZyo6ds/edit?usp=sharing

Or if you think there is a better way of reaching my end goal (slide 2), I
would be interested in hearing your thoughts.
Thanks

Thanks

Le gach dea ghui,
*Shane Carey*
*GIS and Data Solutions Consultant*


On Tue, Oct 16, 2018 at 6:38 AM Johannes Radinger <
johannesradinger at gmail.com> wrote:

> It seems that would would like to have your floodplain cut based on the
> columns of the underlying raster-resolution (and not perpendicular to the
> river line as initially stated). You could use mapcalc to generate a column
> raster map (r.mapcalc expression="colmap = col()") which you could then
> transform to a vector map and use to intersect with your floodplain vector.
>
> best
> Johannes
>
> On Tue, Oct 16, 2018 at 1:24 AM Shane Carey <careyshan at gmail.com> wrote:
>
>> Hi All,
>>
>> I don't think v.transects is going to work for me as lines appear to be
>> cutting across each other. Is there another tool in Grass that can cut the
>> floodplain polygon into 5m lengths (as green lines in image attached)
>>
>> Thanks
>>
>>
>>
>> On Luan 15 DFómh 2018 at 15:38, Shane Carey <careyshan at gmail.com> wrote:
>>
>>> Great thanks, is there anything available that will snap these lines to
>>> the polygon edges?
>>>
>>> Thanks
>>> Le gach dea ghui,
>>> *Shane Carey*
>>> *GIS and Data Solutions Consultant*
>>>
>>>
>>> On Mon, Oct 15, 2018 at 3:30 PM Markus Neteler <neteler at osgeo.org>
>>> wrote:
>>>
>>>> On Sun, Oct 14, 2018 at 11:28 PM Shane Carey <careyshan at gmail.com>
>>>> wrote:
>>>> >
>>>> > Hi,
>>>> >
>>>> > I need to cut a floodplain polygon into one meter strips which are
>>>> perpendicular to the river. This needs to be an automated process. Just
>>>> wondering has anyone ever done this or similar in Grass GIS through python
>>>> or a bash script?
>>>> >
>>>> > The link attached shows two slides. Stage one is the first slide and
>>>> slide two is what I hope to end up with.
>>>> >
>>>> >
>>>> https://docs.google.com/presentation/d/1x7IQ3BJlLLSb6R2atxIIiaeWzyCqCZQ3uWaGPZyo6ds/edit?usp=sharing
>>>>
>>>> This addon seems to do (similar) perpendicular line creation:
>>>>   v.civil - Generates a alignment for designing roads, channels, and
>>>> ports in civil engineering
>>>>   https://grass.osgeo.org/grass7/manuals/addons/v.civil.html
>>>>
>>>> Best
>>>> Markus
>>>>
>>>> --
>>>> Markus Neteler, PhD
>>>> http://www.mundialis.de - free data with free software
>>>> http://grass.osgeo.org
>>>> http://courses.neteler.org/blog
>>>>
>>> --
>> Le gach dea ghui,
>> *Shane Carey*
>> *GIS and Data Solutions Consultant*
>> _______________________________________________
>> grass-user mailing list
>> grass-user at lists.osgeo.org
>> https://lists.osgeo.org/mailman/listinfo/grass-user
>
>
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