FWI - index požarne ogroženosti

[Marko27]

Pozdravljeni,

kot lastnik amaterske vremenske postaje, že dober mesec uporabljam software FWI-calc za izračun požarne ogroženosti okolja (http://wilddata.org.nz/fwicalc/index.php). Podatkov sicer, še ne posredujem na mojo spletno stran (http://www.okroglovreme.com), saj bi rad prej iz angleščine prevedel opise, pomene vseh indeksov ki jih program izračuna... FWI naj bi se sicer uporabljal tudi v Sloveniji, vendar na netu ne dobim nobenega vira?!?
Stvar bi v končni fazi izgledala nekako tako http://www.softrock.co.nz/mg/index.php?page=33

za prevesti oz tolmačiti v Slovenščini pa bi bilo naslednje:

FFMC (Fine Fuel Moisture Code)
This is a numerical rating of the moisture content of surface litter and other cured fine fuels. It shows the relative ease of ignition and flammability of fine fuels. The moisture content of fine fuels is very sensitive to the weather. Even a day of rain, or of fine and windy weather, will significantly affect the FFMC rating. The system uses a time lag of two-thirds of a day to accurately measure the moisture content in fine fuels. The FFMC rating is on a scale of 0 to 99. Any figure above 70 is high, and above 90 is extreme.

DMC (Duff Moisture Code)
DMC is a numerical rating of the average moisture content of loosely compacted organic layers of moderate depth. The code indicates the depth that fire will burn in moderate duff layers and medium size woody material. Duff layers take longer than surface fuels to dry out but weather conditions over the past couple of weeks will significantly affect the DMC. The system applies a time lag of 12 days to calculate the DMC. A DMC rating of more than 30 is dry, and above 40 indicates that intensive burning will occur in the duff and medium fuels. Burning off operations should not be carried out when the DMC rating is above 40.

DC (Drought Code)
The DC is a numerical rating of the moisture content of deep, compact, organic layers. It is a useful indicator of seasonal drought and shows the likelihood of fire involving the deep duff layers and large logs. A long period of dry weather (the system uses 52 days) is needed to dry out these fuels and affect the Drought Code. A DC rating of 200 is high, and 300 or more is extreme indicating that fire will involve deep sub-surface and heavy fuels. Burning off should not be permitted when the DC rating is above 300.

ISI: (Initial Spread Index)
This indicates the rate fire will spread in its early stages. It is calculated from the FFMC rating and the wind factor.

The open-ended ISI scale starts at zero and a rating of 10 indicates high rate of spread shortly after ignition. A rating of 16 or more indicates extremely rapid rate of spread.

BUI (Build Up Index)
This index shows the amount of fuel available for combustion, indicating how the fire will develop after initial spread. It is calculated from the Duff Moisture Code and the Drought Code.

The BUI scale starts at zero and is open-ended. A rating above 40 is high, above 60 is extreme.

FWI (Fire Weather Index)
Information from the ISI and BUI is combined to provide a numerical rating of fire intensity - the Fire Weather Index. The FWI indicates the likely intensity of a fire.

The FWI is divided into four fire danger classes:

Low 0 - 7 Moderate 8 - 16 High l7 - 31 Extreme 32+

FFDC (Forest Fire Danger Code)
Based on predicted generated "fire intensity (kw/m²)" in forest type vegetation (pine, beech). This code denotes how difficult it would be to control a fire in this vegetation type should one start. (Low, Moderate, High, Very High, Extreme)

SFDC (Scrub Fire Danger Code)
Based on predicted generated "fire intensity (kw/m²)" in scrub type vegetation (manuka, gorse, broom). This code denotes how difficult it would be to control a fire in this vegetation type should one start. (Low, Moderate, High, Very High, Extreme)

GFDC (Grass Fire Danger Code)
Based on predicted generated "fire intensity (kw/m²)" in grass type vegetation (dry grass, tussock). This code denotes how difficult it would be to control a fire in this vegetation type should one start. (Low, Moderate, High, Very High, Extreme)




Hvala za morebitno pomoč in lep pozdrav!


Marko

[Marko27]

...nekako sem uspel, kljub nepoznavanju gasilskega izrazoslovlja stvar prevesti. Najbolj sem si pomagal z nekaterimi hrvaškimi stranmi. Na hrvaškem namreč DHMZ uporablja kanadsko metodo FWI za napovedovanje meteorološke požarne ogroženosti. Sicer se pa ta metoda uporablja v večini EU držav. Slovenija je ena redkih, ki se tega, vsaj kar sem uspel izvedet dobrega sistema ne poslužuje. ...še link će koga zanima http://www.okroglovreme.com/wxfwi.php

[Peter]

Na ARSO sem poslal vprašanje zakaj Slovenija uporablja svoj model za napovedovanje požarne ogroženosti in ne Kanadskega modela, ki naj bi se pokazal za najbolšega na področju Sredozemlja, kot je to navedeno na
http://www.okroglovreme.com/wxfwi.php in kako izračunavajo indeks. Odgovor je spodaj.

Spoštovani,

poznamo tudi kanadsko metodo za izračun indeksa požarne ogroženosti (FWI), vendar smo se pred davnimi leti (leta 1994) vseeno odločili za bolj enostavno metodo, ki so jo uporabljali v takratni vzhodni Nemčiji. Seveda smo metodo prilagodili našim zelo raznolikim klimatskim razmeram. Podobno kot pri kanadski metodi izračunamo indeks požarne ogroženosti na osnovnih meteoroloških podatkih, to je: temperature in vlage zraka, hitrosti vetra, količini padavin, razvojni fazi rastlinstva in pozimi tudi višini snežne odeje. Pred kratkim smo razširili izračun indeksa požarne ogroženosti na 16 krajev. Kaj je najboljše ali slabše pa bi težko sodil. Metoda, ki jo uporabljamo, se je zelo dobro izkazala za naše razmere.

Lep pozdrav

Andrej Pečenko

[Marko27]

Glede na napisano, gre očitno za precej podobni metodi!
Škoda le, ker ARSO-va metoda ni nikjer javno zapisana.
FWI namreč lahko računa vsak lastnik amaterske vremenske postaje, saj so vsi parametri za izračun indeksov znani.