Dynamic change of forest fire with topographic factors in Southwest China from 2003 to 2020 based on MODIS data
Southwest China,represented by Yunnan,Guizhou,Sichuan and Chongqing,is ranked as the second-largest natural forest in China,and is also one of the areas with the most serious forest fire disasters.Hence the research,which quantifies the relationship between topographic factors and spatial distribution of forest fire,is in urgent need and can provide us with a scientific understanding of future climate change influence on natural forest fires.In this study,the statistical relationship and change trends between Southwest China forest fire and topographic factors under climate change were analyzed,where MODIS fire data(MCD14DL,from 2003 to 2020),DEM,and historical climate data were used and combined with data statistics approaches,nuclear density analysis and M-K trend test.The results showed that:(1)forest fires in Southwest China illustrated a decreasing trend from 2003 to 2020,with an annual decreasing rate of 42 times per year and the forest fire mainly occurred in winter and spring.Spatially,the overall spatial pattern was gradually decreasing from southern Yunnan to northern Sichuan.Besides,forest fires were mainly distributed in Ailao Mountain,Hengduan Mountain and Panzhihua.(2)For the average from 2003 to 2020,forest fires had a single-peak relationship with mountain altitude and slope,reaching the peak at altitude of 1400-1600 m and slope of 15-20 °,respectively.Sunny slope was the most,half shade half sunny slope was the least.(3)Under the regional climate change conditions,forest fire appeared"spatial transfer"phenomenon.The increase of relative humidity and precipitation at 600 m to 1200 m resulted in a significant decrease in forest fires at this altitude but an increase at middle and high altitudes above 1400 m.The increase of annual average temperature led to the"lifting"of forest fire from the slope of 20-25° to above 35°.Based on above analysis,it can be concluded that under climate change,forest fires in Southwest China have shifted to high altitude and high slope,resulting in the weakening of flammability barrier at high altitude and high slope.
forest firealtitudeslopeaspectclimate changeSouthwest China
万方数据
