| As a natural disaster that causes serious harm to the forest ecosystem and its animal and plant communities,forest fire will not only damage the natural resources on which human society depends for survival and development,but also threaten the life and property safety of surrounding residents,which has a great obstacle to the sustainable development of human society.Using satellite remote sensing image data to assess the fire risk in forest areas can provide a certain scientific basis for the rational allocation of fire resources and the effective prevention of forest fire.Based on satellite remote sensing images,this paper constructed a forest fire risk assessment system,which takes the risk of disaster pregnant environmental factors,vulnerability of disaster bearing bodies and exposure of disaster bearing bodies as secondary indicators,and 12 impact factors such as elevation,annual precipitation,vegetation cover type,TVDI,population density and net primary productivity as tertiary indicators.The risk zoning maps of secondary indicators and total indicators of forest fire in Sichuan province were drawn by using Arc GIS software,and completed the forest fire risk classification in each region.Finally,the hot spot distribution map of forest fire in Sichuan province was used to verify the risk assessment results of each index,which provides a certain reference for the allocation of fire resources and forest fire prevention in various regions of Sichuan province.The main research results are as follows:(1)The weight values of each secondary and tertiary index in the evaluation system were calculated by the fuzzy analytic hierarchy process,the risk zoning map of each secondary index and the total index was obtained by using the superposition analysis tool in Arc GIS,and the area proportion of different risk levels of each index was obtained by data extraction and statistical analysis.The results showed that the largest proportion of regional area in each risk grade of hazard pregnant environmental factor risk index,hazard bearing body exposure index,hazard bearing body vulnerability index and total forest fire risk index were grade II,grade III,grade IV and grade III respectively,and the proportion of regional area was 22.84%,22.37%,23.07% and 25.52%respectively;Among the different risk levels of each indicator,the lowest proportion of regional area was level 5,level 5,level 5 and level 2,and the proportion of regional area was 16.32%,16.28%,16.57% and 15.16%respectively.(2)Based on the index risk zoning map,the index risk data of cities and autonomous prefectures in Sichuan province were extracted by using the mask extraction tool of Arc GIS,and the average index risk and the overall index risk grade of each region in Sichuan province were obtained through statistical analysis.For the general index of forest fire risk,Panzhihua city and Chengdu city had higher average index risk,with average index values of 6.371 and 6.377 respectively,and the overall index risk level was five;Ganzi Tibetan Autonomous Prefecture had a low average index risk,with an average index value of 5.752,and the overall index risk level was grade II;The average value of forest fire risk indicators in Sichuan province was 5.996,and the overall index risk level was grade III.(3)Based on the distribution map of forest fire hot spots in Sichuan province from 2011 to 2020,the index risk grades of each fire hot spot were extracted and statistically analyzed by using the extraction and analysis tool of Arc GIS,and the proportion of the number of forest fire hot spots in different risk grade areas of each index was obtained to verify the accuracy of the assessment results.The results showed that the sum of the number of forest fire hot spots in the areas with the risk grade of grade III or above of the hazard pregnant environmental factor risk index,the vulnerability index of disaster bearing body,the exposure index of disaster bearing body and the total index of forest fire risk was 80.90%,73.52%,77.54% and 82.42% respectively,which proved that the risk assessment results of each grade II index and the total index were accurate. |
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