• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1526-1530
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• 2007

In this study, the chukwookee data were evaluated by applying that for the historical rainfall frequency analysis. To derive a two parameter log-normal distribution by using historical data and modern data, censored data MLE and binomial censored data MLE were applied. As a result, we found that both average and standard deviation were all estimated smaller with chukwookee data then those with only modern data. This indicates that rather big events rarely happens during the period of chukwookee data then during the modern period. The frequency analysis results using the parameters estimated were also similar to those expected. The point to be noticed is that the rainfall quantiles estimated by both methods were similar, especially for the 99% threshold. This result indicates that the historical document records like the annals of Chosun dynasty could be valuable and effective for the frequency analysis. This also means the extension of data available for frequency analysis.

• Atmosphere
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• v.34 no.4
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• pp.337-347
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• 2024

This study reevaluated the Chukwookee precipitation records of the Diary of the Royal Secretariat and The Record of Daily Reflections, which are highly regarded as unprecedentedly long continuous meteorological records in world history. I have reconstructed them called "Hanyang Rainfall Data Set" (1770~1907). This dataset focuses on increased rainfall during 'leap monthly years' compared to regular years. Based on the analysis of First Hanyang Rainfall Data Set, leap monthly years (1,273.4 mm) were +6.0% higher than the overall annual average (1,201.6 mm), and +9.8% higher than 'non-leap monthly years' (1,159.6 mm). Upon further review using Second Modern Rainfall Data Set (1908~2019, 112 years), leap monthly years (1,369.1 mm) showed a +3.2% increase compared to the overall annual average (1,326.9 mm), and a +5.1% increase compared to non-leap monthly years (1,302.6 mm), demonstrating a consistent trend. When consolidated over the longest span of 250 years in Third Seoul Rainfall Data Set (1770~2019), leap monthly years (1,316.1 mm) were found to be +4.6% higher than the overall annual average (1,257.8 mm), and +7.5% higher than non-leap monthly years (1,223.8 mm). Furthermore, examining annual rainy days, leap monthly years in "Hanyang Rainfall Table" (56.3 days) showed a +3.9% increase compared to non-leap monthly years (54.2 days), indicating an overall increase in rainy days during leap monthly years. The occurrence of such peculiar increases in rainfall during leap monthly years could be attributed to meteorological changes throughout the year, caused by the additional intercalary month. However, specific academic discussions require consultation and evaluation from the meteorological community.

• The Korean Journal of Applied Statistics
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• v.13 no.2
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• pp.525-540
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• 2000

Characteristics of precipitation in Seoul have been examined by using long-term observational data. Precipitation records from modern rain gauges were used for 1908-1996, together with the traditional Korean rain gauge (called Chukwookee) observations for 1777-1907. A linear trend analysis of seasonal total rainfall shows no significant trends over the last 200 years A wavelet transform analysis was performed to figure out the transient variations of precipitation.

• Journal of Korea Water Resources Association
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• v.40 no.11
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• pp.851-859
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• 2007

In this study, the chukwookee data were evaluated by applying that for the historical rainfall frequency analysis. To derive a two parameter log-normal distribution by using historical data and modem data, censored data MLE and binomial censored data MLE were applied. As a result, we found that both average and standard deviation were all estimated smaller with chukwookee data then those with only modern data. This indicates that rather big events rarely happens during the period of chukwookee data then during the modern period. The frequency analysis results using the parameters estimated were also similar to those expected. The point to be noticed is that the rainfall quantiles estimated by both methods were similar. This result indicates that the historical document records like the annals of Chosun dynasty could be valuable and effective for the frequency analysis. This also means the extension of data available for frequency analysis.