• Journal of Korea Water Resources Association
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• v.33 no.3
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• pp.307-314
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• 2000

This study is to investigate the recurrence characteristics of wet and dry years using over 200 year records of annual rainfall depth including Chosun Age in Korea. As well as analyzing the correlation structure of the raw data, recurrence trends of wet and dry year has been investigated based on several truncation levels (mean, $mean{\pm}0.25stdv.,\;mean{\pm}O.5stdv.,\;mean{\pm}O.75stdv.,\;mean{\pm}stdv.$). Also the transition probability among wet, dry and normal years has been derived for the same truncation levels. and finally the average return periods based on the steady-state probabilities were obtained. This analysis has been applied to not only the entire data but also partial data set of before- and after-the long dry period around 1900 in order to compare and detect the possible difference between the Chukwooki (an old raingauge invented in Chosun age) and the modem flip-bucket style. As a result, Similar pattern of dry and wet year recurrence has been found, but the return period of extremely dry years after the dry period shown longer than that before the dry period. Assuming that the dry and wet years can be defined as $mean{\pm}$ standard deviations, respectively, the return period of the wet years is shown to be about 5~6 years and that of the dry years about 6~7 years.