Analysis of the spatiotemporal variation in the comprehensive intensity of regional heavy rainfall events in Liaoning province from 1961 to 2021

This study uses daily precipitation data from 61 national meteorological stations in Liaoning province from 1961 to 2021.A range of methods, including the percentile method, standardization processing method, correlation coefficient method, and weighted comprehensive index method were employed.Five assessment indicators for regional heavy rainfall events in Liaoning province were selected: maximum event precipitation, maximum daily precipitation, maximum hourly precipitation, heavy rain coverage, and duration.A quantitative assessment model for regional heavy rainfall events was established to analyze the spatiotemporal variation characteristics of the comprehensive intensity of regional heavy rainfall in Liaoning province.The results indicate that regional heavy rainfall events in Liaoning province occur from April to November, with a general duration of 1 to 4 days and a coverage of 4 to 30 stations.The frequency and comprehensive intensity of heavy rainfall are highest in summer, followed by autumn, and lowest in spring.Heavy precipitation levels above the heavy rain threshold are most frequent in the southeastern part of Liaoning, with strong precipitation more common in the southern part during spring, and in the southeastern part during summer and autumn.There is a significant interdecadal variation in the frequency and intensity of regional heavy rainfall events in Liaoning province.In the 1970s, heavy rainfall events were less frequent, whereas from the early 1980s to the present, they have been more frequent.The comprehensive intensity of regional heavy rain was stronger from the mid-1970s to the early 21st century, and has been weaker since the start of the 21st century.