云南省红河州森林防火期卫星热源点时空分布特征及其风险评估研究

TEMPORAL AND SPATIAL DISTRIBUTION CHARACTERISTICS AND RISK ASSESSMENT OF SATELLITE HEATPOINTS DURING THE SEASON OF FOREST FIRE PREVENTION IN HONGHE PREFECTURE OF YUNNAN PRORINCE

基于GIS技术探讨云南省红河州森防期卫星热源点时空分布特征,并从气象致灾因子和孕灾环境进行森林火灾风险评估。结果表明:(1)红河州12月至次年5月森防期2012~2021年累年平均卫星热源点416个/a,最多年745个,最少年121个;2015年以来热源点呈减少趋势;(2)热源点集中在中北部4个县市(占71%),高密度区1~3月增加且自北向南变化;(3)热源点面积与最高气温和平均气温均呈正相关,与降水量呈负相关;(4)坡度≤15°地区,热源点随坡度增加而增加,坡度>15°地区呈减少趋势;不同坡向热源点发生频率由大到小依次为:东南、西南、南、东、西、西北、东北、北、平坡;有89%的热源点集中在海拔1 000~2 000 m的地区;林地和草地(共占86%)发生热源点最多,其中灌木林多达31%;距离居民点0.5~2 km的缓冲区很容易出现热源点(73.5%)。

Based on GIS technology, the temporal and spatial distribution characteristics of satellite heatpoints during the season of forest fire prevention in Honghe Prefecture were discussed, and the forest fire risk was evaluated from disaster causing factors and disaster pregnant environment.The results show that:(1)In terms of time, there are 416 annual heatpoints, the most in 2014(745)and the least in 2021(121).It has a decreasing trend since 2015.(2)Spatially, the heatpoints are concentrated in 4 cities in the North Central regin of Honghe prefecture(71%),and the high-density area increased from north to south in January to March.(3)The area of heatpoints is positively correlated with the maximum temperature and average temperature, and negatively correlated with precipitation.(4)The heatpoints increases in the area with slope less than 15 degrees, and decreases in the area with slope greater than 15 degrees.The occurrence probability of heatpoints in different slope directions is as follows: southeast, southwest, south, east, west, northwest, northeast, north and flat slope.The heatpoints are concentrated in the area with an altitude of 1 000~2 000 m(89%).Forest land and grassland(86%)are the mainland use types with heatpoints, among which shrub forest occurs most(31%);The heatpoints are the most(73.5%)between 500~2000 meters in the buffer zone of residential areas.