• Title/Summary/Keyword: standard normal probability density function

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Agro-climate Characteristics and Stability in Crop Production of Daegwallyeong Area in Korea (기상자료 분석을 통한 대관령 지역의 작물 최저 한계온도일 추정)

  • Ryu, Jong-Soo;Lee, Jeong-Tae;Lee, Gye-Jun;Oh, Dong-Shig
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.6
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    • pp.1153-1156
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    • 2012
  • Daegwallyeong area to be formed along the mountainous terrain more above 800 m of sea level is known as the cold zone to occur frequently wind, rain and fog. This study to evaluate the stability of crop production and agricultural production potential in the Daegwallyeong was calculated for the low temperature frequency of occurrence and potential evapotranspiration changes with announce the release of Korea Meteorological Administration (KMA) from 1972 to 2009 up to 38 years. Evapotranspiration calculated FAO and other international standard method authorized under the PENMAN-MONTEITH Method was used, and the low temperature onset and frequency of the Gumbel probability density function was used. As a result, the variation of day evaporation for 38 years were showed to respectively width of variation from maximum $9mm\;day^{-1}$ to minimum $0.5mm\;day^{-1}$. The frequency of reappearance to first emergence day that lasts more than 5 days with temperature $5^{\circ}C$ over is 3 April a 50-year frequency, 10 April a 25-year frequency, 20 April a 10-year frequency, 28 April a 5-year frequency, 8 May a 2-year frequency. Psychrotrophic crop to growth temperature more than $5^{\circ}C$ can be secured to stable production with planting after May 8, prior to planting for normal growth can be seen that the risk of growth.