• Title/Summary/Keyword: Clark

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A Sensitivity Analysis for Parameters Effection upon the Design Floods: Natural Watershed (설계홍수량에 영향을 미치는 매개변수의 민감도 분석: 자연유역을 중심으로)

  • Yun, Yeo-Jin
    • Journal of Korea Water Resources Association
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    • v.31 no.6
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    • pp.695-708
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    • 1998
  • Recently, it seems increasing trends that the design floods on the middle and small scale of urban regions and natural basins are evaluated with introducing to the concept of the critical storm duration. However the study of the critical storm duration is not sufficient and especially on the natural basins, it rarely performed. therefore in this study, estimated the critical storm duration and peak discharge according to the rainfall distribution type, the position of peak rainfall intensity, and the frequency on the natural basins were evaluated using Clark model and the influence of each factors on the design floods was analyzed with sensitivity analysis on the parameters of the model.

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Flood Discharge Analysis on Land Use Changes in Han Stream, Jeju Island (토지이용변화에 따른 한천유역의 홍수유출 변동 분석)

  • Yang, Se-Chang;Yang, Sung-Kee;Lee, Jun-Ho;Jung, Woo-Yul;Ko, Kwang-Hyo
    • Journal of Environmental Science International
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    • v.24 no.4
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    • pp.425-435
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    • 2015
  • A number of projects for development have been done continuously due to the increase of tourist in Jeju Island. However flood disaster countermeasure due to urbanization is not considered during this development projects. This study is to make basic process for the flood estimation in Han stream of Jeju Island. The variation of stream discharge due the every 5 years' land use change from 1980 to 2005. Data for flood events (rainfall and discharge) were collected for HEC-HMS model. Clark method was used for unit hydrograph analysis. For the estimation of Clark unit hydrograph parameters, Kraven II and Sabol's empirical equations were applied. The peak discharge increased 9.9~33.67% and total discharge amount increased 12.53~30.21%. Also, time of concentration for peak discharge was reduced by 10 minutes for each event.

A Study on Tertiarization in Korea: Test of Baumol's Hypothesis (한국의 서비스화에 대한 연구: Baumol 가설을 중심으로)

  • Seo, Hwan-Joo;Lee, Young-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.1
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    • pp.143-150
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    • 2007
  • Using a panel data of Korea for $1979{\sim}2002$, this study investigates the determinants of the service sector employment share in Korea. In order to analyze the impact of macroeconomic factors on the service sector's employment share we estimate a simple panel model which is in line with Baumol's model. The panel GMM estimation results show that: 1) The increase in the share of service-related jobs in total employment tends to rise with GDP per capita, which confirms demand-bias hypothesis proposed by Clark. 2) We find that a crucial role in this process has been played by the productivity gap. As Baumol's hypothesis or Baumolis disease, the expansion of the employment share in services relative to industry is the direct consequence of services' lower productivity performances.

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Analysis of Flood Runoff Hydrograph by Parameter Estimation Technique (매개변수 산정기법에 따른 홍수유출 수문곡선 분석)

  • Choi, Jong-In;Lee, Dong-Hoon;Yi, Jae-Eung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.873-877
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    • 2012
  • 지형인자는 하천유역의 홍수량을 산정하는데 있어 매우 중요한 인자이다. 유역의 지형인자를 통해 홍수유출 모형에 적용하기 위한 매개변수를 산정하고 강우-유출모형에 적용시켜 홍수수문곡선을 추정하고 있다. 그러나 우리나라에 적합한 매개변수의 추정방법은 아직 미흡하여 외국에서 개발된 경험식을 주로 이용하고 있다. 본 연구에서는 하천유역의 홍수유출을 계산할 때 입력인자로 사용되는 집중시간 및 저류상수 등과 같은 매개변수를 산정하는데 있어 사용되는 경험식들의 조합에 따른 홍수유출량의 변화양상을 분석하였다. 시험유역으로 청미천 유역을 선정하여 각 경험식에 따른 매개변수를 산정하여 비교하였다. 강우-유출 모델로 HEC-HMS를 적용하였으며 모의시 관측된 강우 자료를 전 유역에 걸쳐 분포시키기 위하여 IDW(Inverse Distance Weighted) 방법을 사용하고 공간적으로 분포된 강우자료와 지형자료를 이용한 유출모의가 가능하도록 ModClark(Modified Clark) 방법을 사용하였다. 또한, 중규모 이상의 큰 유역의 경우는 유입시간이 유하시간에 비해 상대적으로 짧아 유입시간을 무시하고 유하시간을 집중시간으로 취급하므로 각 소유역에 대한 집중시간 산정은 유하시간을 산정하는 방법을 적용하였다. 본 연구에서는 집중시간 및 유하시간 산정에 Kirpich, Rziha, Kraven(I), Kraven(II) 공식을 적용하였고, 저류상수 산정에 Clark, Linsley, Sabol, Russel, Peters 공식을 적용하였다.

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