Abstract:

The forest lightning fire of Daxinganling mountains was highly happened in frequency in China, the integrated index study on the forest lightning fire is very important to monitor, early warn and administrate the forest lightning fire, and to protect forest resource. Based on lightning observation data from 2005 to 2007, daily meteorological observation data and history record data of the forest lightning fire from 1965 to 2007 in Daxinganling mountains of Heilongjiang Province, the important influence of the factors was analyzed on the forest lightning fire, these factors include lightning firebrand, forest type distribution related to fuel, and initial spread speed of forest fire related to meteorological condition. The integrated index model for the forest lightning fire was established with weighting analysis method. The integrated index model is ITDX=0.3ILDX+0.5ISDX+0.2IFTDX,the ITDX is the integrated index of the forest lightning fire in the model, the ILDX is the lightning firebrand index, the ISDX is the index for the initial spread speed of forest fire related to meteorological condition, the IFTDX is the index for forest type distribution related to fuel, the ITDX is 0 when the daily rainfall is above 8.8 mm. The index calculation method of the ILDX, ISDX and IFTDX were introduced in the paper. The calculated value extent of the integrated index ITDX is between 0 and 1.0. The results showed that, the ITDX calculated value of the integrated index is bigger, the dangerous degree of the forest lightning fire to happen is higher. The forest lightning fire is the extremely dangerous and likeliest happening when ITDX≧0.9, it’s highly dangerous and likelier happening when 0.9>ITDX≧0.7, it’s middle or low dangerous and likely happening when 0.7>ITDX≧0.4, it’s no danger and no happening when 0.4>ITDX. The synthesis influence for the forest lightning fire could be effectively reflected in the integrated model by means of the factors, which include lightning firebrand, forest type distribution related to fuel, and initial spread speed of forest fire related to meteorological condition, the results was in accordance with the dangerous degree of the forest lightning fire environment and the actual happened condition of the forest lightning fire in Daxinganling mountains. The model application could provide a certain clue to the monitoring and early warning for the dangerous degree of the forest lightning fire.