Abstract:
Yunnan is a major forestry and agriculture province in China, where large-scale biomass combustion occurs every year. It causes atmospheric pollution and economic losses and impacts human health. Using MODIS satellite fire products, this study analyzed the temporal and spatial distribution characteristics of biomass burning in Yunnan Province from 2010 to 2019. We explored the affecting factors with data on land use, digital elevation model, population, and precipitation in the area. The study results showed that the number of fire spots in Yunnan Province has generally shown a decreasing trend in the past ten years. The peak of fire spots occurs from February to April every year, which total number accounts for 67% of the whole year. It is mainly because of the seasonal combustion of straw and precipitation. The fire spots drop sharply from June and remain at a low level until the end of December. The spatial distribution diversity of fire spots is mainly due to the different land-use types in the study area. The 10-year total of forest fires is the highest in Yunnan Province, reaching 50%, followed by grassland fires and cropland fires. Fire spots are concentrated at an altitude of 1000 meters to 2000 meters but are less distributed in areas below 1000 meters where the population is concentrated. Typical areas of fire concentration are Pu'er, Wenshan, Honghe, and Xishuangbanna, which had about 60% fire points in the province. These areas are the central sugarcane-producing regions, resulting in a more concentrated biomass burning phenomenon.