[GRASS-user] how to create parameters for run r.ros for fire simulation

[Margherita Di Leo]

Hi,

I'll try to answer up to my wits' end (inlines)

On Thu, May 23, 2013 at 2:17 PM, sittichai choosumrong <
sittichai.ocu at gmail.com> wrote:

>
> My question is, How can I create and get the values of the parameters as
> shows below;
>
> *model=*name Name of an existing raster map layer in the user's current
> mapset search path containing the standard fuel models defined by the USDA
> Forest Service. Valid values are 1-13; other numbers are recognized as
> barriers by r.ros.
>
The fuel model, as stated, refers to the 13 standard fuel models defined by
the USDA Forest Service. If you don't dispose of a fuel map, you can try to
define the fuel by your expert judgement, with the help of this publication:
http://www.fs.fed.us/rm/pubs_int/int_gtr122.pdf

> *moisture_1h=*name Name of an existing raster map layer in the user's
> current mapset search path containing the 1-hour (<.25") fuel moisture
> (percentage content multiplied by 100).
>
This refers to moisture content in dead fuel. There are (fortunately)
empirical formulas that relate this with the Fine Fuel Moisture Code
(FFMC), which depends on temperature and relative humidity of the air. See
the publications of the Canadian Forestry Service for further details.

> *moisture_10h=*name Name of an existing raster map layer in the user's
> current mapset search path containing the 10-hour (.25-1") fuel moisture
> (percentage content multiplied by 100). *moisture_100h=*name Name of an
> existing raster map layer in the user's current mapset search path
> containing the 100-hour (1-3") fuel moisture (percentage content multiplied
> by 100).
>
These two are linked to the previous one by an empirical relationship,
already implemented in GRASS, so that you may want to deduce only one of
the three by the FFMC and let GRASS calculate for you the other two. Of
course this doesn't apply in case you have plenty of information about the
site in object and you want exploit them all.

> *moisture_live=*name Name of an existing raster map layer in the user's
> current mapset search path containing live (herbaceous) fuel fuel moisture
> (percentage content multiplied by 100).
>
This refers to the moisture content in live fuel, and depends on the state
of vegetation, which has a seasonal trend. It may vary from 50 in dry
season up to 500 in wet season (in Europe!). But this parameter should
really be calibrated on the basis of the vegetation present in the area and
of the climatic region.
Please note that this module isn't a mere calculation but the
implementation of a model (Rothermel's) and it's based on other models (the
ones you apply to get the fuel models and the other parameters), so that
you will deal with uncertainties and all the implications that modelling
implies.

Hope this helps,
madi

-- 
Best regards,

Margherita DI LEO
Postdoctoral Researcher

European Commission - DG JRC
Institute for Environment and Sustainability (IES)
Via Fermi, 2749
I-21027 Ispra (VA) - Italy - TP 261

Tel. +39 0332 78 3600
margherita.di-leo at jrc.ec.europa.eu

Disclaimer: The views expressed are purely those of the writer and may not
in any circumstance be regarded as stating an official position of the
European Commission.
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