[GRASS-user] accumulate a raster following the flow accumulation

[Giuseppe Amatulli]

Thank Johannes!!!
right! I make some test and yes if you provide the flow=temp the output
accumulation will be the accumulation of the temp weighted by the area of
each cell.

So if i divide  temp_accumulation / flowaccumulation i get the upper-stream
mean temperature.

Thank you very much
Giuseppe




On 5 May 2018 at 16:21, Johannes Radinger <johannesradinger at gmail.com>
wrote:

> Giuseppe,
> you could use the "flow" option in r.watershed: flow=temperature
> (result=accumulative temperature in drainage basin upstream). And then you
> could calculate another run of r.watershed with a flow map with values =1
> (result = accumulative drainage basin upstream, cell count). Dividing both
> maps provides a map of average temperature upstream.
>
> HTH
> J
>
> On Sat, May 5, 2018 at 8:51 PM, Giuseppe Amatulli <
> giuseppe.amatulli at gmail.com> wrote:
>
>> Hi,
>> I'm searching for a GRASS command that is able to "accumulate" a raster
>> following the flow accumulation output obtained by r.watershed.
>>
>> In other words if I have a temperature raster I would like to
>> accumulate the temperature values following the drainage direction. The
>> final results would to get the mean of the uppers stream temperature (so
>> accumulation_temperature / flowaccumulation).
>>
>>  r.accumulation input=temperature  flowaccumulation=flow accumulation
>> output=acc_temperature
>>
>> It is something that exist?
>>
>> Thank you
>> Giuseppe
>>
>>
>> --
>> Giuseppe Amatulli, Ph.D.
>>
>> Research scientist at
>> Yale School of Forestry & Environmental Studies
>> Yale Center for Research Computing
>> Center for Science and Social Science Information
>> New Haven, 06511
>> Teaching: http://spatial-ecology.net
>> Work:  https://environment.yale.edu/profile/giuseppe-amatulli/
>>
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>>
>
>


-- 
Giuseppe Amatulli, Ph.D.

Research scientist at
Yale School of Forestry & Environmental Studies
Yale Center for Research Computing
Center for Science and Social Science Information
New Haven, 06511
Teaching: http://spatial-ecology.net
Work:  https://environment.yale.edu/profile/giuseppe-amatulli/
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