Abstract:In order to gain a deep understanding of the spread characteristics of two wildfires that occur simultaneously, as well as the impact of atmosphere, terrain, and other factors on different wildfire behaviours, and to provide scientific support for extinguishing multiple wildfires. Two wildfires that occurred in Fuling on August 17, 2022 are selected to analyse and study the behaviour of the two wildfires using highresolution geographic information, vegetation data, and meteorological observations. At the same time, numerical simulation is conducted using the wildfireatmosphere coupled WRFFire model (Weather Research and Forecasting Model with Fire Module). The research results are found as follows. (1) Under the control of deep and high pressure, the two wildfires break out under the background of continuous high temperature and dryness. Ten days before the wildfire, the daily average temperature is 5.2-8.8 ℃ higher than the same period as usual, the daily maximum temperature is 6.2-8.4 ℃ higher than the same period as usual, and the daily average relative humidity is 26.3% lower than the same period as usual. The drought meteorological level reaches severe drought, and the fire risk meteorological level is high or extremely high. (2) The test results show that the simulated wind direction and wind speed changes of the model are relatively consistent with the actual situation, basically reflecting the sudden changes in wind direction and wind speed of the fire site, indicating that the WRFFire can accurately reproduce the spread of multiple real fire sites at the same time. (3) The analysis of temporal and spatial changes in wildfires spread characteristics indicates that the wildfire development in Daliangshan can be divided into 6 stages during this simulation phase, and the wildfire in Beishanping can be divided into 4 stages. The main reason for the difference in the spread and development of the two fires with a linear distance of 4.4 km is the difference in local wind fields caused by differences in terrain. There is a southwestnortheast trumpetshaped terrain on the south side of the Daliangshan fire site. After passing through this terrain, southerly winds form a significant convergence on the northeast side. Therefore, during the northward spread and development of the fire site, the fire on the east side is greater than that on the west side. The terrain on the west side of the Beishanping fire site is higher than that on the east side. As the southerly wind advances northward, it forms convergence in front of the mountain. Therefore, during some periods, the fire is stronger on the west side of the fire site in front of the mountain.