PROGRESS IN GEOGRAPHY ›› 2012, Vol. ›› Issue (1): 46-55.doi: 10.11820/dlkxjz.2012.01.007

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Changes of Intensity and Frequency of Typhoon Heavy Rainfall Events in Eastern Taiwan during 1960-2009

CHANG Poyu   

  1. Department of Culture and Natural Resources, NUTN, Tainan 70005, Taiwan
  • Received:2011-03-01 Revised:2011-06-01 Online:2012-01-25 Published:2012-01-25

Abstract: In this study, the typhoon rainfall data of Ilan, Hualian, Chengkung, Taitung, Dawu and Lanyu weather stations located in eastern Taiwan during 1960-2009 are concerned. With the criteria of the issuing of typhoon warnings and 24-hours maximum rainfall above 50 mm, typhoon-induced heavy rainfall events were identified. Trend change and periodic change in the series of 24-hours maximum rainfall are taken as the intensity indicator and the annual number of heavy rainfall events was examined by using some nonparametric statistical methods. The results of data collation show that the number of target events ranges from 117 to 151 stations within the target period of study. Station-based analysis demonstrated that no significant change was found in the intensity series of typhoon heavy rainfall events in the study area. In contrast, there is a periodic increase in frequency of typhoon- induced heavy rainfall events. This change also implies that potential of hydrological and geological hazards will become higher. It is required that all these hazards be taken notice of in the future for disasters prevention.

Key words: eastern Taiwan, frequency, intensity, periodic change, trend change, typhoon heavy rainfall