[GRASS-user] how to calculate volume of water stored in water storage with r.sim.water?

[bonushenricus]

Hi Anna
I too immediately thought it was enough to compute it for the final
step of the simulation,
but I noticed that the same slope, same ditches, same rainfall, for two
reservoirs at the same location, same length along a contour, but
different width and depth, at the final step of the simulation the
water depth was always 30 cm, I went to read the article 
Mitasova, Helena, Chris Thaxton, Jaroslav Hofierka, Richard McLaughlin,
Amber Moore, e Lubos Mitas. «Path Sampling Method for Modeling Overland
Water Flow, Sediment Transport, and Short Term Terrain Evolution in
Open Source GIS». In Developments in Water Science, 55:1479–90.
Elsevier, 2004. https://doi.org/10.1016/S0167-5648(04)80159-X
where I read the Saint-Venant equation. I am an agricultural technician
and geographer unfortunately ignorant of hydrological calculations and
serious mathematics, and I understood, looking at the equation, that
the water depth is the depth of overland flow = rainfall exces - water
flow.
So the final 30 cm should not be understood as accumulated water, but
as the blade of water that was added at that precise moment.
Isn't my interpretation right?
-- 
-- 
Perito agrario Enrico Gabrielli
progetto F.A.R.M. www.farm-agroecologia.it
Tessera n. 633 Collegio Periti agrari prov. Di Modena
Biblioteca agricoltura: https://www.zotero.org/groups/aplomb/
https://www.inaturalist.org/observations/bonushenricus


Il giorno lun, 31/07/2023 alle 14.34 -0400, Anna Petrášová ha scritto:
> 
> 
> On Sun, Jul 30, 2023 at 6:01 AM bonushenricus
> <bonushenricus76 at gmail.com> wrote:
> > Hi
> > From r.sim.water, how can I calculate the volume of water stored in
> > small water storages placed along a relief and connected to
> > ditches?
> > In this article https://doi.org/10.1016/j.agwat.2023.108398 these
> > Italian researchers with r.sim.water manage did this calculation,
> > but I
> > do not understand how. With a calculation at different times on
> > discharge at the entrance to the water storage?
> > I tried to contact them, but they did not reply.
> > Thanks!
> > 
> 
> 
> Hi,
> 
> volume would be simple depth times cell size squared for a certain
> selected area. I would compute it for the final step of the
> simulation, I am not sure what is the purpose of summing it for
> different time steps. Perhaps you could clarify a little bit?
> 
> Anna
>  
> > -- 
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