A Fire Danger Rating System for Israel

(IFFN No. 8 January 1993, p. 12-14)


Background:
In 1989 a team of experts from the U.S. Forest Service visited Israel to study the forest fire Management situation here and make recommendations for the establishment of a forest fire danger rating system along the lines of the system in operation in the U.S. As a result of this, a joint team from Israel's Forest Department and Meteorological Service was sent to the U.S. to learn about their National Fire Danger Rating System (NFDRS) and consider how it could be adapted for use in Israel. As one outcome of this team's concluding recommendations, a project was started to develop a fire danger rating system for Israel. This project is headed by a research meteorologist and funded by the Forest Department.

Initial Efforts:
During the first stage of the project, historical weather and fire occurrence data were collected. At the same time, the NFDRS computer program which calculates fire danger indices was obtained and the literature of this system was studied (References). The objective in mind was to adapt the program for use in Israel. Our efforts were given a significant push forward by the timely visit of two American Fire Weather Meteorologists who greatly aided us in clarifying our objectives and priorities. Their observations concerning some unique aspects of fire weather in Israel were also very valuable. During the second stage, an Israeli Fire Danger Rating System was developed whose main characteristics are outlined below. Summer 1992 has been this system's "check-out" fire season.

The System:
Danger ratings are calculated on a regional basis, Israel being divided into seven regions. Each region has roughly homogeneous climatic and physiographic features. Up to three meteorological stations were chosen as being representative of each region. 

Observations from these stations are transferred daily from the Meteorological Service's mainframe computer to the PC/AT 386 on which the danger rating system operates (Fig.1). The transferred data are reformatted into a weather file which fits the input requirements of the NFDRS program which calculates fire indices.

Also required by the NFDRS program is a file containing the site data (altitude, slope, aspect, fuel type, etc.) for each of the representative meteorological stations. The indices produced are both displayed graphically and stored for further analysis. The graphic display also shows indices calculated on the basis of 24-hour and 46-hour forecasts. The two main indices utilized by us thus far are the ignition component (IC), which reflects the ease with which fuels can be ignited, and the burning index (BI), indicating the severity of fires once they occur, both in terms of spread rate and intensity. Running the program on about ten years of historical data allowed for the regional determination of index threshold values for three levels of fire danger (low, medium, high). Forecasted fire danger levels are transmitted (by fax) from the Meteorological Service to the Forest Department, Fire Fighting Center, and the National Fire Brigades Commissioner. Within the Forest Department the three danger levels are the basis for determining the size of stand-by initial attack crews and the positioning of fire trucks and other equipment.

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Fig.1. Fire Danger Rating System Flow Diagram

 

Long-term Support:
The budget for the system's operation and maintenance is expected to be provided jointly by the Forest Department and the Ministry of the Interior (responsible for fire brigades). In order to create a permanent position of fire weather meteorologist, an "agricultural desk" was created within the Meteorological Service. This position combines the functions of agricultural meteorologist in the winter (e.g. freezing forecasting) and fire weather meteorologist during the fire season. This insured the financial support of a third body, the Ministry of Agriculture.

First Season Results:
Preliminary analysis comparing the system's danger ratings with data on actual fires (Tab.1,2) indicates that the system can provide an extremely useful indication of fire occurrence and severity. We hope in the coming seasons to "fine tune" the system, in accordance with accumulating experience.

 

Tab.1. Percent of the total days at each danger level during which the number of fires indicated occurred
(Judea Mountains Area, Israel)

Ignition Component (IC) Danger Rating

Number of Fires per Day

None

1-3

>3

Low (61 days)

90 %

10 %

 
Medium (85 days)

48 %

47 %

5 %

High (24 days)

17 %

71 %

12 % 

 

 

Tab.2. Percent of the total days at each danger level during which the total area burned was as indicated
(Judea Mountains Area, Israel).  

Burning Index (BI) Danger Rating

Daily Area Burned (ha)

<1

2-10

>10

Low (48 days)

98 %

2 %

 
Medium (99 days)

85 %

7 %

8 %

High (23 days)

60 %

26 %

13 % 

 

References:
Bradshaw, L.S., J.E. Deeming, R.E. Burgan and J.D. Cohen (comps.) 1984. The 1978 National Fire-Danger Rating System: Technical Documentation. USDA For.Serv.Gen. Tech.Rep.INT-169.
Burgan, R.E. 1988. Revision to the 1978 National Fire-Danger Rating System. USDA For.Serv.Res.Pap.SE-273

 

 

From:
John Woodcock

Address: 

Land Development Authority
Forest Department
P.O.Box
Kiryat-Hayim 26103
ISRAEL

Fax: +972-4-411971

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