[GRASS-user] Question about unidimensional and bidimensional waterflow analysis

GRASS GRASS user
1

Hi to all, Actually I'm working in my final degree project, the project on
which I work wants to make a comparison study between a study of waterflow
hazard in a unidimensional and bi-dimensional models.

Can GRASS work in bi-dimensional algorithms (for example r.dam)?

I know that r.inund.fluv works in unidimensional (like Hec-RASS), but i
don't know if GRASS have algorithms to work in bi-dimensional to calculate
plains inundation.

Thanks to all.

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2

Hi Diego,

I answer also to your question of yesterday about damflood.

  • r.inund.fluv use a quasi-2D approach, but is not an hydrodynamic model. It is only a way to export result of a 1D hydrodynamic model on an high resolution DEM in order to obtain flooding map.

  • r.damflood use a 2D approach even if we have only performed test with dambreak initial condition and with a landslide generated tsunami. If you go on the addon page (http://grasswiki.osgeo.org/wiki/AddOns/GRASS7/raster#r.damflood) you find the SWE.c library that solve the shallow water equations in GRASS using a finite volume method as detailed described in Cannata M. & Marzocchi R. (2012). Two-dimensional dam break flooding simulation: a GIS embedded approach. - Natural Hazards 61(3):1143-1159

Finally r.dam is only a grass script which take advantage of r.lake in order to create a reservoir that is one of the needed inputs of r.damflood command.

I hope to answer to your questions…for further doubts do not hesitate to contact me.
Best regards,
Roberto

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2013/10/24 Diego Mérida López <dmerida80@gmail.com>

Hi to all, Actually I’m working in my final degree project, the project on
which I work wants to make a comparison study between a study of waterflow
hazard in a unidimensional and bi-dimensional models.

Can GRASS work in bi-dimensional algorithms (for example r.dam)?

I know that r.inund.fluv works in unidimensional (like Hec-RASS), but i
don’t know if GRASS have algorithms to work in bi-dimensional to calculate
plains inundation.

Thanks to all.

–
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3

Ok, thank you for your response.

I was reading the articles in the morning.

It would be possible to use GRASS for a flood study of a river or stream in
a 2D system (as you can see I am not an expert on this subject and my
answers may be obviously... sorry)? I think that is possible with the
combination of r.inund.fluv and r.damflood (how you says in the article THE
CONTRIBUTION OF GIS IN FLOOD MAPPING. TWO APPROACHES USING OPEN SOURCE GRASS
GIS SOFTWARE).

I'm really interested in work with libre/OpenSource programs to do it, I
know programs that can work in 2D for that purpose, but aren't open source
and have EULA... not good.

I'm a noob in GRASS GIS. I was searching in the descriptions of algorithms
and not found any information if it's possible or not.

I'm really grateful for your help.

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4

On 24/10/2013 18:11, Diego Mérida López wrote:

Ok, thank you for your response.

I was reading the articles in the morning.

It would be possible to use GRASS for a flood study of a river or stream in
a 2D system (as you can see I am not an expert on this subject and my
answers may be obviously... sorry)? I think that is possible with the
combination of r.inund.fluv and r.damflood (how you says in the article THE
CONTRIBUTION OF GIS IN FLOOD MAPPING. TWO APPROACHES USING OPEN SOURCE GRASS
GIS SOFTWARE).

It is possible, but now we do not have developed it, because we are searching for funding to do it.
It is a good research opportunity because we have already written a library to solve the SWE (2d equation of flow) that can be applied outside of the river, but the 1D equation on the river need to be considered at least with a tighly coupled integration with the GIS..

I'm really interested in work with libre/OpenSource programs to do it, I
know programs that can work in 2D for that purpose, but aren't open source
and have EULA... not good.

I'm a noob in GRASS GIS. I was searching in the descriptions of algorithms
and not found any information if it's possible or not.

I'm really grateful for your help.

Sorry for my late answer,
Best regards,
Roberto

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