Characteristics of Flash Heavy Rainfall Events in Summer in Shijiazhuang and Their Impact Factors

Qian Weimiao; Wu Lu; Li Guocui; Cao Yue; Li Xiliang

doi:10.16765/j.cnki.1673-7148.2024.06.004

Abstract：Using the hourly rainfall data observed at added times by 215 encryption automatic weather stations in Shijiazhuang from June to August in 2013 to 2020 and the mathematical and statistical meth-ods,this article analyzes the fine-scale characteristics of flash heavy rainfall(FHR)events and rainstorm in summer as well as the impact factors.It is found that the summer FHR events in Shijiazhuang have the characteristics of less frequency,scattered high frequency area and strong locality.The proportion of au-tomatic weather stations on the slopes of[200,600)m in the high-frequency areas of FHR events is the largest,and the occurrence frequency of FHR events in mountain areas above 600 m height is reduced.The High-frequency areas of FHR events are related to mountain orientation and topographic slope.The duration of FHR events in mountain areas is longer than those in plain,but the hourly rainfall intensity is weaker than in plain.In Shijiazhuang,63.6％of rainstorm days are accompanied with FHR events,and the proportion of rainstorm days with FHR events descends with the increase of terrain height and reduc-tion of rainstorm days.The number of flash heavy rainfall stations decreases rapidly with the enhancement of hourly rainfall intensity,but the diurnal variation of the number of stations with flash heavy rainfall above 60 mm·h-1 is not obvious.The average hourly rainfall intensity shows a diurnal variation of multi-ple peaks.The high-frequency areas of FHR events in Shijiazhuang have strong local characteristics.FHR events occurring under weak synoptic-scale forcing are difficult to forecast,and their geographical environment and local characteristics need to be further analyzed.