[GRASS-user] Sentinel2- flooding

[Shane Carey]

Great thanks

On Aoine 7 Noll 2018 at 19:14, Stefan Blumentrath <
Stefan.Blumentrath at nina.no> wrote:

> Hi Shane,
>
>
>
> Following up on robertos answer:
>
> You could try the Normalized Difference Water Index (NDWI) which is
> computed for S-2 as:
>
> ndwi = (B08-B11)/(B08+B11)
>
> or alternatively
>
> ndwi = (B03 - B08) / (B03 + B08)
>
> See e.g.:
> https://github.com/sentinel-hub/custom-scripts/blob/master/sentinel-2/ndwi/script.js
>
>
>
> You could also take a look at Sentinel-1 for flooding / water bodies.
> However, Sentinel-1 would have to be pre-processed in SNAP/gpt.
>
>
>
> Cheers
>
> Stefan
>
>
>
> *From:* grass-user <grass-user-bounces at lists.osgeo.org> *On Behalf Of *Shane
> Carey
> *Sent:* fredag 7. desember 2018 17:35
> *To:* roberto.marzocchi at gmail.com
> *Cc:* grass-user grass-user <grass-user at lists.osgeo.org>
> *Subject:* Re: [GRASS-user] Sentinel2- flooding
>
>
>
> Ok, thanks.
>
> Le gach dea ghui,
>
> *Shane Carey*
>
> *GIS and Data Solutions Consultant*
>
>
>
>
>
> On Fri, Dec 7, 2018 at 2:45 PM Roberto Marzocchi <
> roberto.marzocchi at gmail.com> wrote:
>
> I Think there isn't any tool pre-configured. You need to find an index to
> calculate "flooded" cells and then you can simply use r.mapcalc
>
>
>
> R
>
>
>
> Il giorno ven 7 dic 2018 alle ore 14:45 Shane Carey <careyshan at gmail.com>
> ha scritto:
>
> Hi,
>
>
>
> I've obtained an image from sentinel2 where it shows flooding. Just
> wondering are there tools in Grass to classify an image in order to pull
> out these "flooded" pixels?
>
>
>
> Thanks
>
> --
>
> Le gach dea ghui,
>
> *Shane Carey*
>
> *GIS and Data Solutions Consultant*
>
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>
> --
Le gach dea ghui,
*Shane Carey*
*GIS and Data Solutions Consultant*
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