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

[Johannes Radinger]

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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