The characteristics and future projections of fire danger in the areas around mega-city based on meteorological data-a case study of Beijing

It is crucial to investigate the characteristics of fire danger in the areas around Beijing to increase the accuracy of fire danger monitoring, forecasting, and management. Using meteorological data from 17 national meteorological stations in the areas around Beijing from 1981-2021, this study calculated the fire weather index (FWI) and analyzed its spatiotemporal characteristics. It was found that the high and low fire danger periods were in April-May and July-August, with spatial patterns of "decrease in the northwest-increase in the southeast" and a significant increase throughout the areas around Beijing, respectively. Next, the contributions of different meteorological factors were quantified by the multiple regression method. We found that during the high fire danger period, the northern and southern parts were affected by precipitation and minimum relative humidity, respectively. However, most areas were influenced by wind speed during the low fire danger period. Finally, comparing with the FWI characteristics under different SSP scenarios, we found that the FWI decreased during high fire danger period and increased during low fire danger period under different SSP scenarios (i.e., SSP245, SSP585) for periods of 2021-2050, 2071-2100, 2021-2100, except for SSP245 in 2071-2100 with an increasing trend both in high and low fire danger periods. This study implies that there is a higher probability of FWI in the low fire danger period, threatening the ecological environment and human health. Therefore, it is necessary to enhance research on fire danger during the low fire danger period to improve the ability to predict summer fire danger.