RETURN PERIOD AND THE TREND OF EXTREME DISASTROUS RAINSTORM EVENTS IN ZHEJIANG PROVINCE

作者：陳海燕,余暉,葉庚姣,徐明,楊秋珍

摘要：A provincial Disaster-causing Rainstorm Severity Index(DRaSI) is introduced to quantify the relationship between rainfall and its disastrous impacts on Zhejiang province of China, shortened as ZJ-DRaSI. ZJ-DRaSI is set up based on the DRaSI for single stations in combination with the coverage of rainstorms. The probability distribution function(PDF) of ZJ-DRaSI between 1971 and 2015 can be well fitted by the Wakeby Distribution with five parameters. It is found that decadal(e.g. 10 yr, 20 yr, and so on) return period values of ZJ-DRaSI related to typhoons are generally lower than that of non-typhoon events, implying that disastrous non-typhoon events have a higher frequency of occurrence. The extreme typhoon events have a significant cycle of 22.5 years, while the non-typhoon events have a significant cycle of 15 years. Both are currently at the high-value phase. The annual extreme value of ZJ-DRaSI exhibits an increasing trend of approximately 15% every 10 years.

發文機構：Zhejiang Provincial Meteorological Observatory Shanghai Typhoon Institute of CMA Guangxi Meteorological Service Center

關鍵詞：EXTREMEdisastrousRAINSTORMeventPROBABILITYdistributionRETURNperiodTREND

分類號： P426.616[天文地球—大氣科學及氣象學]