Temporal and Spatial Distribution Characteristics of Short-term Heavy Precipitation in Panzhihua in Recent Ten Years

Using hourly precipitation observation data of Panzhihua from May to October during the period of 2013—2022, the spatiotemporal distribution characteristics of short-term heavy precipitation with different intensities in Panzhihua and the relationship between short-term heavy precipitation and altitude were statistically analyzed. The results show that from 2013 to 2022, the short-term heavy precipitation in Panzhihua showed an increasing change from south to north. The short-term heavy precipitation from June to September mostly occurred in the northwest, and the regional concentration characteristics of short-term heavy precipitation in May and October were not obvious. The interannual distribution of the frequency of short-term heavy precipitation in the past 10 years was uneven. The frequency was the highest in 2017 and the least in 2022. The largest annual increase was in 2016 and the largest decrease was in 2019. The short-term heavy precipitation mainly occurred from June to September, significantly less in May and October. The ten-day variation characteristics showed a tripodal distribution, with the three peaks appeared in late June, late July and early September respectively. The diurnal variation characteristics showed an obvious unimodal type, with the peak appearing at 04:00. Short-term heavy precipitation was more likely to occur at night and significantly reduced during the day. In different altitude ranges of Panzhihua, both the average frequency of short-term heavy precipitation and the average annual precipitation increased with the increase of altitude.