| This study used regional spatial data of forest fire disaster,meteorological data and forest data from 2003 to 2016.By using ArcGIS and SPSS,the researcher analyzed the pattern of forest fire occurrence in Pu'er,Yunnan.In addition,the study had deep exploration on the factors of fire,weather and forest combustibility,in order to manage forest fire effectively in Pu'er,Yunnan.The study got the following results:1.The occurrence of forest fires in pu 'er city from 2003 to 2016 has fluctuated greatly in time,and its main forest fire risk level is general forest fire.Forest fire frequency and fire area are experiencing interannual declining,However,the pattern of forest fire frequency and fire area in the month and day scale has increased,and then declined.forest fire frequency and fire area peaked in 2004 and 2010.Respectively,The periods of 2004 to 2005 and 2009 to 2010 have high frequencies of forest fires.In the season pattern,most forest fire emerged in spring.Most of forest fires usually occur during January to June,and the highest frequencies is in April.12:00 to 17:00 is a high incidence period,the number of forest fires and the area of fire reached a peak between 14:00 and 16:00.The change in the size of the area over the course of a day is roughly the same as the number of fires,but it does not fit perfectly.Winter and spring are the main fire prevention period of forest fire in pu'er city.2.There are obvious differences in the severity of forest fire in each district and county in pu 'er city.The area having the highest number of fires is Lancang County,with 167 forest fires,and Ximeng County has the lowest number of fires,only nine times.The disaster area of lancang county,the largest area of the area of forest fire,was 965.04 hectares,and Ximeng County had the smallest area of forest fires,only 19.85 hectares.According to the cluster analysis,the districts and counties of pu'er city are divided into three fire insurance grades.LanCang county belongs to ? level of forest fire danger rating,NingEr county and JingDong county belong to ? level of forest fire danger rating,SiMao district,ZhenYuan county,JingGU county,MoJiang county,JiangCheng county,MengLian county and XiMeng county belong to grade ? fire danger rating.3.The occurrence of forest fires in pu 'er is mainly affected by meteorological factors such as temperature,precipitation and wind speed.The precipitation mainly concentrated on April to October,Forest fires in the city mainly distributed from February to May.The average precipitation had a negative relationship with the frequency of forest fires.The average monthly wind speed in pu 'er city started to rise in January,peaked in March and April,and gradually declined in May.The trend of average wind speed has the same pattern with forest fires.The average wind speed is positively correlated with the number of forest fires.The annual temperature change remain relatively stable,and rising temperature may increase the possibility of occurrence of forest fires,however,the occurrence of fire is not only influenced by temperature,also affected by many factors such as rainfall and human activities.4.The main fire source of forest fire in pu'er city is man-made fire source.In the forest fire which has been identified,man-made fire source accounts for 93.37%.In man-made fires,the number of forest fires caused by burning fires accounted for 65.36%of the total number of fire fires,and the proportion of man-made fires was 58.45%.The forest fires in pu'er city mainly occur in coniferous forest and broad-leaved mixed forest,among which the coniferous tree species is dominated by Pinus kesiya var.langbianensis,and broad-leaved tree species are distributed with wood,southwest birch,eucalyptus and so on.According to the spatial and temporal patterns of the occurrence of forest fires,and forest species composition and fire source.For a region of space-time laws extremely forest types,forest fire factors etc.It can be seen that a region of the fire danger of forest fire area is geographically dispersed,Managers should be aimed at LanCang county and NingEr county and other key areas to focus on prevention and control of fire risk,And it is necessary to conduct education for the public in fire season,during February to May,and improve forest fire precaution and fire belt construction,practical and effective to forest fire prevention. |
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