24th Pacific Science Congress (PSC-24)

Precipitation-induced disasters are the primary natural risk factor threatening railway safety. In this study, three types of precipitation warning thresholds for railways under the jurisdiction of various Railway bureaus (RB for short) in China—namely, patrol dispatch, speed restriction, and line closure—were used as railway safety indicators to investigate the impact of historical and future changes in extreme precipitation on railway safety. The key findings are as follows: (1)Over the past decade, the total annual precipitation of Guangzhou, Nanchang, and Nanning RB has decreased by 9.6-33.7 mm; in contrast, that of Zhengzhou, Jinan, and Xi'an RB has increased by 24.5-29.6 mm. (2)Over the past decade, the variation characteristics of extreme precipitation intensity (which significantly affects railway safety) have differed from those of annual total precipitation. The Shenyang RB has seen the most significant increase in extreme precipitation intensity, while the Nanning RB has experienced the largest decrease in this regard. (3)Over the past decade, the number of hours of railway precipitation warnings has shown a distribution pattern of "decrease in the south and increase in the north". Specifically, the patrol dispatch warning hours of the Guangzhou RB have decreased by 25.9 hours, while those of the Zhengzhou RB and Chengdu RB have increased by 14.8 hours and 7.7 hours, respectively. Among all RBs, the Chengdu RB has recorded the largest increases in both speed restriction (+3.5 hours) and line closure (+2.0 hours) warning hours, making it the core area facing the greatest pressure in railway safety prevention and control.(4)Projections under the SSP1-2.6, SSP2-4.5, and SSP5-8.5 scenarios indicate that both precipitation and the number of hours of railway warnings in the 21^st century will be higher than those in the 20^th century. Moreover, the higher the warning level, the larger the proportion of increase. In the late 21^st century, the national average hours of patrol dispatch, speed restriction, and line closure warnings will increase by 175%, 463%, and 647%, respectively. Among all RB, the Chengdu RB will have the largest increase in warning hours, making it a key focus for future railway safety defense efforts.

 

Extreme precipitation, Railway, Rainfall Warning Threshold, Rainfall Warning Risk Hours, Global warming