Analysis of Topographic Features Based on Yunnan Fire

The Yunnan power grid has the characteristics of wide distribution and large geometric size, which makes the power grid vulnerable to natural disasters such as wildfires. The unique topography and climatic conditions of transmission lines crossing mountains, forests and other zones can easily lead to the outbreak of mountain fires, or even the tripping of transmission lines. In serious cases, transmission towers may be destroyed, thus causing major power accidents. The occurrence of mountain fire is closely related to topographic factors, and the change of each topographic factor (elevation, slope, slope direction, etc.) has a certain influence on fire. This paper mainly studies the relationship between three terrain factors and fire. Based on the statistical analysis of remote sensing data from 2005 to 2020, the terrain features and their influence of fire spots in Yunnan province were analyzed. The results show that most of the fires occur within the range of 1000-2000m above sea level, and the fires occur frequently. The frequency of fire occurring below 1000m and above 2000m is low. The occurrence frequency of fire is higher in the gentle slope range, among which, the number of fire point samples is the largest within the range of 5°-15°, followed by 0°-5°and less than 15°.In this paper, eight slopes are divided to make statistics of fire points, and the number of fires in different slopes also fluctuates, among which the south slope has the highest fire risk, accounting for 16.0%.The West Slope accounted for only 10.0%, with the lowest fire risk. Terrain factor is a fixed variable that has a fixed influence on the regional fire risk. Therefore, terrain analysis of fire is of great significance for the prevention of mountain fires in power grid.