Research On Temporal Distribution Characteristics Of Urban Fire System

With the rapid development of national economy in recent years, the country’s urbanization rate soared at an average annual rate of 1.35%. The urban number increases year by year, a large amount of Social wealth gathered here. Fire hazards infested make urban fire’s multiple tendencys inevitable. With the enhancing of national quality, the current fires appeared a downward trend, but the total number of urban fire remains high, the fire situation is still not optimistic. The importance of urban fire research is enhanced.According to the fire data of Wuhan, Lanzhou and Harbin, this paper mainly researched the occurrence regularity of urban fire incident. The regularity can provide a theoretical basis for building an urban fire forecast and warning platform. At the same, it can also provide an inspection standard of this platform.In order to explore the temporal distribution characteristics of urban fire system,we applied statistical analysis methods of Coefficient of variation, Fano factor, Allan factor and Interevent-Interval histogram. Using above methods. It is found that urban fire sequence exist scaling behaviors, and long-range correlation characteristics.As the urban fire is a complex system with a variety of factors. In this paper, we studied the stability and universality of fire time sequence’s fractal features. The research mainly carried out from three aspects, they are the geographical location, the total length of time and time window T. The research founded that urban fire have stable fractal self-similarity characteristics within a large time range. The presence of this characteristic has nothing to do with the selection of time window T and the geographical position of the city.In addition, as a non-stationary time series sequence, the non-stationary property of urban fire data may lead to "spurious regression". In order to solve this problem, we carried on the further research using Detrended Fluctuation Analysis. The results show that time interval sequence of urban fire has a long-range negative correlation and meets power-law relationship.Finally, through setting different loss threshold, the article made a concrete analysis of urban fire data. It is found that the urban fire’s Zipf figures have some sharedcharacteristics. When the direct economic loss of urban fire is more than 500￥, The Zipf figures meet good power-law relationships, and the frequency of urban fire decreases with the increase of direct economic loss. Analysis urban fire sequence under different loss threshold on the time scales. We can see that with the increase of damage threshold, scaling law index of time sequence gradually reduce. Especially for great fire,it tends to a Poisson distribution.