Analysis Of The Current Situation Of Forest Fires In Liaoning

The four seasons in Liaoning are distinct,and forest fires are more common,often causing large forest fires.In order to understand the current situation of forest fires in Liaoning,this paper comprehensively analyzes the frequency,occurrence season,peak period,occurrence reason,forest type that is prone to forest fire and crown fire,forest age that is prone to crown fire,etc.based on the records of historical fire archives in Liaoning Province to provide reference for forest fire prevention work in Liaoning Province in the future.The specific research results are as follows:(1)The data statistics method was used to analyze the frequency of forest fires in Liaoning Province in the past 30 years,and the fire occurrence trend was studied.At the same time,the season and peak period of Liaoning forest fire occurred in the past 10 years were analyzed with the 30-and 10-day method.The results show that the frequency of forest fires in the province has accumulated 4,697 times in 30 years,and the annual average frequency has reached 156.56 times.Fire alarms and general fires occur frequently,accounting for 84.09% of the total,and the frequency of major fires is low,accounting for 15.94% of the total.A mega forest fire did not occur.During the period from the Eighth Five-Year to the Twelfth Five-Year Plan,the overall frequency of fires,the frequency of fire alarms,and the frequency of general fires increased with time,while the frequency of large fires gradually decreased with time.(2)The forest fires in the province have obvious seasonality,mainly in spring,autumn and winter.The most frequent occurrences in spring are concentrated in March,April and May,accounting for 80.37% of all forest fires.The forest fire mainly occurs in the spring from late March to late April,and the peak period occurs from mid-April to late April.Therefore,it can be determined that the Liaoning region is an important martial law period for forest fire prevention from late March to late April.There are certain differences in the peak period of forest fires in various regions.The Liaodong region has two peak periods throughout the year in late April and late October;Forest fires in western Liaoning occurred in three peak periods in late March,late April and late November;in southern Liaoning,the highest peak is in late April and late November;in northern Liaoning,the highest peak is in late April and late November;and in central Liao,the peaks are in mid-February,late March,late April and late November.(3)The analysis of the causes of forest fires in Liaoning using historical statistical analysis shows that natural factors and human factors coexist.Natural factors occasionally cause lightning or spontaneous combustion in some areas,and the overall occurrence is slighter.The human factor is the most important cause of forest fires.The artificial production fire accounts for 27.39% of all human fires.Among them,three main reasons are burning,burning land grid and burning straw.Artificial non-productive fire accounts for 70.59% of all human fires.Among them,burning papers for the dead and wild smoking are the two main reasons.(4)Statistical analysis of forest types that have experienced forest fires in Liaoning with data analysis shows that: the forest types with the most fires are barren hills,broad-leaved trees,natural mixed forests,artificial pine forests,eucalyptus natural pure forests,sea buckthorn artificial pure forests,Pinus tabulaeformis-eucalyptus mixed forest,Pinus tabulaeformis-seabuckthorn mixed forest,Pinus tabulaeformis-mixed mixed forest,and artificial pure forest of larch.The four forest types most likely to have crown fire were Pinus tabulaeformis-Hippophae rhamnoides mixed forest,Pinus tabulaeformis Plantation pure forest,Larix gmelinii plantation young forest and Pinus densiflora-broadleaf mixed forest.The incidence of crown fire was above 75%,followed by seabuckthorn artificial pure forest,Pinus tabulaeformis-eucalyptus mixed forest,Pinus tabulaeformis-mixed mixed forest,Pinus sylvestris var.mongolica plantation,black pine artificial pure forest,fruit forest and scorpion artificial pure forest.The incidence is between 60% and 75%.(5)The forest type with occurrence of crown fire in Liaoning area was analyzed by different forest age analysis methods.The results showed: There are three forest types with 100% probability of crown fire occurrence in young forest,which respectively are larch artificial pure forest,tussah field and scorpion artificial pure forest.There are seven forest types with ?50%-<100% probability of crown fire occurrence,which respectively are Pinus tabulaeformis forest pure forest,Pinus tabulaeformis-mixed forest,artificial forest of Pinus sylvestris var.mongolica,artificial pure forest of Robinia pseudoacacia,natural pure forest of eucalyptus,broad-leaved natural mixed forest and fruit forest.Among the young and middle-aged forests,there are three forest types with ?50% probability of crown fire occurrence,which respectively are Pinus tabulaeformis-eucalyptus mixed forest,artificial forest of Robinia pseudoacacia and barren hill.In the grown forest,there are two forest types with 100% probability of crown fire occurrence,which respectively are black pine artificial pure forest and natural red pine-broad mixed forest,and the incidence of crown fires in other forest types is <50%.