• Title/Summary/Keyword: 수정 IAS 지수

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Estimation of Rainfall-runoff Erosivity Using Modified Institute of Agricultural Sciences Index (수정 IAS 지수를 이용한 강우침식인자 추정)

  • Lee, Joon-Hak;Oh, Kyoung-Doo;Heo, Jun-Haeng
    • Journal of Korea Water Resources Association
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    • v.44 no.8
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    • pp.619-628
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    • 2011
  • The purpose of this study is to evaluate the existing method of calculating rainfall-runoff erosivity using monthly precipitation, such as Fournier's index, modified Fournier's index, IAS (Institute of Agricultural Sciences) index, etc., and to present more reasonable regression model based on monthly rainfall data in Korea. This study introduced a new simplified method of calculating rainfall-runoff erosivity based on monthly precipitation, called by modified IAS index. It was expanded form IAS index which is the simple calculation method by summing up the rainfall amount of two months with maximum amount. Monthly precipitation and annual rainfall-runoff erosivity at 21 weather stations for over 25 years were used to analyze correlation relationship and regression model. The result shows that modified IAS index is the more reasonable parameter for estimating rainfall-runoff erosivity of the middle-western and south-western regions in Korea.

Estimation of Rainfall Erosivity in North Korea using Modified Institute of Agricultural Sciences (수정 IAS 지수를 이용한 북한지역의 강우침식인자 추정)

  • Lee, Joon-Hak;Heo, Jun-Haeng
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.6
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    • pp.1004-1009
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    • 2011
  • Soil erosion in North Korea has been continued to accelerate by deterioration of topographical conditions. However, few studies have been conducted to predict the amount of soil loss in North Korea due to limited data so far. Rainfall erosivity is an important factor to predict the amount of long-term annual soil loss by USLE (universal soil loss equation). The purpose of this study is to investigate rainfall erosivity, which presented the potential risk of soil erosion by water, in North Korea. Annual rainfall erosivities for 27 stations in North Korea for 1983~2010 were calculated using regression models based on modified Institute of Agricultural Sciences (IAS) index in this study. The result showed that annual average rainfall erosivity in North Korea ranged from 2,249 to 7,526 and averaged value was $4,947MJmm\;ha^{-1}\;hr^{-1}\;yr^{-1}$, which corresponded to about 70% of annual average rainfall erosivity in South Korea. The finding was that the potential risk of soil erosion in North Korea has been accelerated by the increase of rainfall erosivity since the late 1990s.

Rainfall Erosivity for Pyongyang in North Korea (평양 지역의 강우침식인자에 대한 연구)

  • Lee, Joon-Hak;Heo, Jun-Haeng
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.458-461
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    • 2015
  • 연구는 북한지역의 표토침식량 산정을 위하여 토양침식을 유발하는 강우침식인자를 산정하고 장기간에 걸친 경향성을 분석하기 위한 연구로서, 대상지역은 평양 관측소 지점의 1981~2014년의 강우자료를 이용하였다. 가용한 북한지역의 강수량은 월강수량이기 때문에, 강우침식인자의 산정은 수정 IAS 지수를 이용한 추정방법과 연강수량을 이용한 추정방법을 적용하였다. 연강우침식인자에 대한 경향성 분석결과 평양지점의 장기간에 걸친 연강우침식인자 값에 대한 뚜렷한 경향성은 발견되지 않는 것으로 나타났다.

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