• Atmosphere
• /
• v.27 no.2
• /
• pp.151-162
• /
• 2017

The rainfall amount data measured by 'Wootaek', a method of measuring how far the moisture had absorbed into the soil when it rains during the Joseon Dynasty, were estimated with the Chugugi data in the 12 sites where both the 'Wootaek' and 'Chugugi' data are available. Excluding the 5 sites (Ganghwa, Jinju, Jeonju, Chuncheon, Hamheung) poor in sample data, the 'Wootaek' data 1 'Ri' and 1 'Seo' in 'Chugugi' unit (Bun) in the 7 sites; Suwon, Gwangju (Gyeonggi-do), Gongju, Daegu, Wonju, Haeju and Pyeongyang, were 11.1/5.6 Bun, 9.4/3.2 Bun, 14.0/5.7 Bun, 9.3/3.9 Bun, 13.6/4.3 Bun, 11.3/4.8 Bun and 16.8/7.4 Bun, respectively. The Chugugi unit 1 'Bun' is equall to approximately 2 'mm'. The average of the 7 sites is 13.1/5.7 Bun, however it becomes small to 11.7/4.5 Bun when the Pyeongyang of which data is considerably distributed over wide range is excluded, showing that the 'Wootaek' data 1 'Ri' is approximately the 2.3~2.6 times of 1 'Seo'. It is recommended to use the individual estimates of the sites in utilizing the 'Wootaek' rainfall data of 352 stations across the country restored from the "Gaksa-deungnok".

• Atmosphere
• /
• v.25 no.4
• /
• pp.719-734
• /
• 2015

Korea is one of the country with the world's oldest meteorological observation records. Starting with first meteorological record of fog in Goguryeo in the year of 34 BC, Korea had left a great deal of quantitative observation records, from the Three Kingdoms Period to Goryeo to Joseon. During the Joseon Dynasty, with a great attention by kings, efforts were particularly made to measure rainfall in a systematic and scientific manner. In the 23rd year of King Sejong (1441), the world's first rain gauge called "Chugugi" was invented; in the following year (1442), a nationwide rainfall observation network was established. The King Sejong distributed Chugugi to 350 observation stations throughout the state, even to small towns and villages, for measuring and recording rainfall. The rainfall observation using Chugugi, initiated by King Sejong, had been in place for about 150 years, but halted during national disturbances such as Japanese invasion of Korea in 1592. Since then, the observation had been forgotten for a long time until the rainfall observation by Chugugi was resumed in the 48th year of King Yeongjo (1770). King Yeongjo adopted most of the existing observation system established by King Sejong, including the size of Chugugi and observation rules. He, however, significantly reduced the number of Chugugi observation stations to 14, and commanded the 352 local authorities such as Bu, Gun, Hyeon to conduct "Wootaek", a method of measuring how far the moisture had absorbed into the soil when it rains. Later on, six more Chugugi stations were established. If the number of stations of Chugugi and Wootaek are combined together, the total number of rainfall observation station in the late period of Joseon Dynasty was 372. The rainfall observation with Chugugi during the Joseon Dynasty is of significance and excellence in three aspects: 1) the standard size of Chugugi was so scientifically designed that it is as great as today's modern rain gauge; 2) rainfall was precisely measured, even with unit of Bun (2 mm); and 3) the observation network was distributed on a nationwide basis.