Abstract:

To reveal the multiscale variation law of extreme precipitation events under climate warming, based on the daily precipitation data of the National Meteorological Station from 1961 to 2020, the spatiotemporal variation characteristics of extreme precipitation events on the monthly scale in Shandong Province were analyzed using the percentile relative threshold method. The results show that the monthly-scale extreme precipitation events in Shandong Province mainly occurred in July and August with the annual frequency bigger than 40%. The annual frequency showed a decreasing trend as one moves from southeast to northwest regions. The annual frequency and precipitation of extreme precipitation events increased in most areas for all seasons except autumn and considerably increased in winter. After the mid-1980s, extreme precipitation events have generally increased and intensified, and their interannual changes have increased significantly. The intensity of extreme precipitation in summer and winter increased significantly by 10 mm to 20 mm during 10 years in summer in the central, southwestern, and peninsular areas of Shandong and 20% to 50% in winter months in Shandong province. The precipitation instability generally increases under climate warming in Shandong, and it is necessary to strengthen early warning and defense services for disaster risks such as rainstorm, flood, and blizzard.

Key words: Shandong Province, extreme precipitation, monthly scale, spatiotemporal distribution, changing characteristics