Analysis of Time Variations in Relative Humidity around a Water Area Using Bowen Ratio

  • Kim, Ki-Young (Department of Global Environment, Keimyung University) ;
  • Kim, Kyu-Rang (Applied Meteorology Research Division, National Institute of Meteorological Research, KMA) ;
  • Kim, Hae-Dong (Department of Global Environment, Keimyung University)
  • Received : 2014.08.25
  • Accepted : 2014.10.20
  • Published : 2014.10.31


The time variations in relative humidity observed at the Gangjeong (Goryeong) Reservoir in the Nakdong River over a one-year period (September 2012-August 2013) were analyzed with the Bowen ratio. The thermal vertical scale of the reservoir was also evaluated following Yamamoto's method. The study's results showed that the relative humidity at the reservoir was higher than that of the Daegu Meteorological Observatory (inland) all year round. The difference was slightly larger at nighttime (17-20 %) than at daytime (13-15 %) in all seasons except summer. The quantitative order of latent heat flux was summer, spring, autumn, and winter. This finding signifies that the thermal vertical scale of the reservoir corresponds to that of a shallow lake. The Bowen ratio was smallest at midday of the summer season. In other words, the net radiation energy was converted more as latent heat flux than sensible heat flux during a higher temperature period.


  1. Henry, J. A., Dirks, S. E., 1985, Urban and Rural Humidity Distributions; Relationships to Surface Materials and Land Use. Journal of Climatology, 5, 53-63.
  2. Hujibe, F., 2002, Long-term Humidity Changes on Hot Days in the Central Part of Tokyo. Tenki, 49, 473-476.
  3. Hujibe, H., 2012, Urban Climate Variation and Abnormal Meteorology, Asakura Press.
  4. Kai, K., 2012, Two Kinds of Warming, Seizando Press.
  5. Kawamura, T., Ono, H., 1993, The Urban Dryness in Japan, Study Group for Climate Impact and Application Newsletter, 9, 39-42.
  6. Kim, K. Y., Byun, J. Y., Kim, H. D., 2013, Heat Island Intensity in Seongseo, Daegu, South Korea a Rural Suburb Containing Large Areas of Water, Journal of Environmental Science International, 22, 1337-1344.
  7. Kondo, J., 1994, Hydro-meteorology, Asakura Press. 161 pp.
  8. Kondo, J., 2000, Surface Boundary Layer Meteorology, Tokyo University Press, 336 pp.
  9. Lee, B., 2002, Daily Variation of Evaporation Observed by a Large-sized Vaporimeter, Journal of Environmental Sciences, 12, 196-199.
  10. Lee, J. J., Lee, B. Y., Lee, H. S., Kim, Y. K., 2013, Automatic Observation of Evaporation at a Dam, Proceedings of the Korean Environmental Sciences Society, 22, 63-65.
  11. Nishizawa, T., 2005, Field Research Method of Climate, Kokon Press, 122 pp.
  12. Park, M. H., Kim, H. D., 2007, A Study on the Characteristics of Urban Dryness in Daegu, Journal of Environmental Sciences, 16, 171-178.
  13. Yamamoto, G., Chein, T., Yasuda, N., Kondo, J., 1972, Evaporation from Deep Lakes in Japan, Journal of Meteorological Society of Japan, 50, 423-430.
  14. Yamamoto, G., Kondo, J., 1964, Evaporation from Lake Towada, Journal of Meteorological Society of Japan, 42, 85-96.
  15. Yamamoto, G., Kondo, J., 1968, Evaporation from Lake Nojiri, Journal of Meteorological Society of Japan, 46, 166-177.

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