Study On Seasonal And Spatial Trend Of Forest Fires In Inner Mongolia Great Khingan

The study of seasonal and spatial trends in forest fires helps to grasp the patterns and changing trends of forest fires,providing scientific basis for the division of fire risk periods and the rational allocation of fire prevention resources.Based on the fire records of Inner Mongolia Great Khingan from 1981 to 2018,this thesis uses mathematical statistics and Mann Kendall trend test to analyze the distribution law and change trend of forest fire frequency and fire danger period,taking year,fire prevention period,season and time point as time scales.At the same time,the frequency,cause,and level of fires were analyzed at the spatial scale of administrative regions and terrain factors.The research results are as follows:1.From 1981 to 2018,the overall forest fires in Inner Mongolia Great Khingan region showed a "ladder like" change,with a trend of first increasing,then decreasing,then increasing,and finally decreasing.The trend of forest fires during the fire prevention period is the same as that of the whole year,with a decrease in the proportion of the total number of fires that year;Forest fires mainly occur in spring,summer,and autumn,with complex changes in spring forest fires,significant fluctuations in summer forest fires,relatively small fluctuations in autumn forest fires,and fewer fires in winter.Forest fires have sudden changes in spring and autumn.The fire danger period in spring has a significant shift and extension towards summer,and then gradually returns to its original position;Forest fires mainly occur during the day,with the highest number of forest fires occurring at noon,with human factors accounting for more than half of the total.Although there are fewer fires in the early morning,they are more likely to lead to serious consequences.2.Forest fires in Inner Mongolia Great Khingan have shown a trend of increasing from southwest to northeast in the Left Banner of Xinbalhu,Ewenke Autonomous Banner,Horqin Right Front Banner,Oroqen Autonomous Banner,and Molidawa Daur Autonomous Banner.The overall number of forest fires in various regions of Inner Mongolia Great Khingan,except for Genhe City,has significantly decreased,with a more significant decrease in the number of forest fires in autumn and winter.3.The number of forest fires in Inner Mongolia Great Khingan decreases with the increase of altitude,with fires occurring below 1000 m accounting for over 90% of the total number of fires.Fires in low altitude areas are mostly forest fires and general forest fires.Although there are fewer fires in high altitude areas,the fire level is relatively high;About 70% of the total number of forest fires occur within a slope of 10°,but the fire level is relatively low,mostly forest fire alarms and general forest fires.There are fewer fires on high slopes,but they are more prone to major and catastrophic forest fires;There are more fires in the southeast and southwest slopes,with a higher level of fire in the southwest slope,and the least number of fires in the northwest and south slopes;The number of fires caused by unknown sources of fire is the highest,followed by artificial fires and production fires,with lightning strikes and underground fires accounting for a relatively low proportion of re ignition.Research suggests that forest fires in Inner Mongolia Great Khingan are influenced by factors such as vegetation types,climate conditions,and human interference.To ensure effective control of forest fires in Inner Mongolia Great Khingan,it is necessary to develop scientific and reasonable management strategies based on the dynamics of forest fires in various regions,and achieve sustainable utilization of forest resources.