The importance degree of weather elements in driving wildfire occurrence in mainland China

Understanding the degree to which weather factors influence fire occurrence is crucial for managing wildfires because China's recent rigorous fire prevention measures have made fire occurrence drivers distinct from those in other nations. This study first examined the features of mainland China wildfires in order to provide an explanation. We used 38,158 confirmed wildfires from 2005 to 2021 and used a partial least squares (PLS) regression model and partial correlation analysis (PCA) to investigate which weather element is more important in driving wildfire occurrence in each of the twelve ecoregions in mainland China. According to the findings, there were less wildfires in mainland China reduced significantly from 2005 to 2021 (R2 = 0.78, P < 0.01), and the fire seasons were varied according to the ecoregions. We discovered using Pearson correlation that weather factors had a significant correlation with the occurrence of wildfires in the majority of locations of mainland China, but at a lower decision level. From the Variable Importance in Projection (VIP) scores of each weather element, we found that humidity and diurnal temperature range (DTR) were more significant than other weather factors in influencing the occurrence of wildfires, especially in southern China. The partial correlation coefficients (Pcor) between weather elements and fire occurrence draw the same conclusion that the driver strength of weather elements is different in different ecoregions. The findings also demonstrated that, on a monthly time frame, weather elements had no delay effect in driving fire occurrence. The impact of forest management laws and fire suppression measures on the frequency of wildfires in mainland China was examined. Instead of focusing on the forecast of fire occurrence, this study investigated which weather factors were more relevant in fire occurrence against the backdrop of tight forest fire prevention and control in China and presented a new perspective on wildfire research and management. This study also will be use as a reference for the nations interested in managing wildfires and emphasizes the significance of human actions in causing wildfires, particularly China's fire suppression practices.