| Forest plays an important role in the national economy. However, as the global climate warming,, frequent forest fires cause great damage to forest resources. The forest fire occurs in spring and autumn season when the weather is dry and the temperature have greater fluctuations. The development of the forest fire is greatly concerned with the early climate background and the weather conditions at the time. Therefore, carrying out the fire forecast, and continuously researching new methods, improving the accuracy of guidance are important to guiding the local forest fire prevention. Forest fire danger grade is a measurement to possibility and extend degree of forest fire happen. Multiple-factor forest fire danger grade forecast is a forest fire meteorological forecast method which considered fully the same day's meteorological elements and cumulate effect variety in three days. In spite of its effect in operational application is well, as a result of correct factors existed, its departures are larger to lighting fire and forest fire extensive spread for drought and cold front occurred in the context of drought. Therefore, Classify the weather situation for large forest fires and lightning fires from 1980 on., unprecedented research work and also the innovation of this paper; combining with the forest fire level forecast and weather situation classification method to predict the large forest fires and the lightning fire, makes more progress from previous that attach important to forest fire danger grade value trend prediction and despise forest fire prone period, prone location prediction research mentality, the research conclusion has practical significance for improving the forest fire forecast.This paper adopts the methods of analyzing and calculating for synoptic and diagnosis climatology, focusing on two aspects researching works. First, introduces some of the basic principles of forest fire forecast, according to statistical analysis for forest fire data 1961-2006 and forest fire danger rating data in period of the spring forest fire prevention 1980-2010 of Heilongjiang province, summed up the high rate characteristics and interdecadal variation of forest fire in Heilongjiang Province in the year 1994-2006. It consistent with the features that high fire early days significantly ahead of time. The period of Spring Prevention of Heihe and DaXingan Mountain is extended ahead of schedule and increasing trend of the times. On this basis, classifying emphatically in synoptic Meteorology forest fire in 1980-2005under the background of the big forest fire weather divided into 4 categories with 8 types:continental high atmospheric pressure warm ridge (the strong warm ridge, Bay Lake low trough cold front). Low vorte (northeast low vortex, low vortex later stage control). Northwest airflow control (Bay Ridge high cold front Northwest Airflow Type, Bay Lake warm high ridge former Northwest Airflow Type, groove ridge mobile), blocking high atmospheric pressure control (Bay Lake blocking high atmospheric pressure type). Second, researching the characteristics of the interdecadal of lightning stroke fire caused by thunderstorm and the characteristics of time and spatial distribution, according to the analytical conclusion that the days of lightning fire is not related to high forest fire days, and the accuracy of lightning fire prediction from the prediction of forest fire danger rating is about 57.7%, put forward the ideas that combined with the use of weather situation classification and forest fire danger rating prediction method to predict the lightning fire, and then summarizes the types of prone to lightning fire weather. Through the single example, catastrophic forest fire and lightning fires have occurred in high forest fire danger rating background. Big forest fire early weather situation suit with the4 categories 8 type classification, compared to pay more attention to the change of lightning fire weather situation classification method, it can better predict the occurrence time and lightning fire prone area. The results are as follows:(1)4805 times forest (grassland) fire happened in Heilongjiang province. The fire area in ninety is far less than that of early eighty's; From the frequency that there are two will occur frequently and two little hair period; From the time of occurrence, the most easily fire happened at 10:00-14:00, the more easily fire happened at 14:00-18:00, and the fire can happen at 18:00-21:00 and 7:00-10:00, and the seldom fires happened at 21:00-7:00.(2)The interdecadal change of the catastrophic forest fire has obvious concentrated period, the fire place mainly in Da xingan mountain and the Xiao xingan mountain, happen is mainly in spring.(3)Forest Fire Danger weather Level index (FFDI) is combustible evaluation index of he potential fire degree which is closely related the forest to weather conditions, the division standard category five, including 4,5 for the high fire level. Multiple factors forest fire danger weather forecast method is one forecast method of Heilongjiang province forest fire forecast methods which are operating in Heilongjiang province meteorological offices.The calculation of the high daily number and the yearly times by the big and Xiaoxingan mountain, the correlation between them is more than 0.6. (4)The classified method of the high fire weather situation, which based on the 49 times catastrophic forest fire weather library, divided the high fire weather situation into 4 groups,8 type, according to the 500 hPa temperature and humidity characteristics.In the earlier stage of forest fire, the main forest fire, very little is a single high altitude area, and most of the situation in the adjustment of several situation or both. When a high fire the weather situation continued some days, the chance of catastrophic forest fire happened a rising trend.(5)Lightening Fire is dangerous natural fire. The big changes year by year, mainly in late spring and summer, day to change characteristics clearly; the space distribution features clearly, mostly appeared in the north, northeast and southeast, Heihe in Yichun mountain. For example, the Daxingan mountain to the number of the High level fire dangerous Lightening Fire year by year and the number of wildfires in no good correlation. On one hand, it is the cause of the data, on the other hand is the multiple factor forest fire forecast method not forecast Lightening Fire level of ability. Based on 185 Lightening Fire the weather examples library, with the weather situation still can be classified into four types and eight type.(6)Meantime, the comprehensive using the inspection multiple factor forest fire forecast method and the weather situation level classification method could forecast the catastrophic forest fire and lightning fire to get to the purpose of improve the prediction rate of forest fire successfully. |
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