• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 춘계학술대회 논문집
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• pp.437-442
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• 2001

In Korea, collapse of railway slopes is frequently occurred due to tycoon or heavy rainfall doling rainy season and has been made personal and social damage greatly. In order to evaluate the stability of railway slopes under rainfall, explanatory variables and subordinate variables were selected for multivariate analysis. The sites which failure had occurred due to rainfall were investigated and critical rainfall was defined by the case that had high value of correlation factor after multivariate analyses for 121 cases had been executed. The maximum hourly rainfall during 24 hours before failure caused the collapse of railway embankment and the 0.3 square value of maximum hourly rainfall during 24 hours before failure caused the collapse of railway cut-slope, From the application to collapse examples, it is judged that critical rainfall curve will be used to estimate the stability of slopes.

• 한국수자원학회논문집
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• 제31권4호
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• pp.375-384
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• 1998

최근 배수시스템의 설계시 임계지속기간의 개념을 도입하여 설계홍수량을 산정하고 있다. 그러나, 임계지속기간 산정시 설계강우분포의 선정은 명확한 기준없이 임의로 사용되고 있다. 따라서 본 연구에서는 중소규모의 도시화된 산본유역에 ILLUDAS 모형을 이용하여 다양한 강우분표형태가 임계지속기간에 미치는 영향에 대하여 분석하였다. 모형결과의 분석으로부터 강우분포형태(등분포, 삼각형분포, 사다리꼴분포, Huff 분포, IDF 를 이용한 중앙집중분포)는 임계지속기간 뿐만 아니라 첨두유량에도 큰 영향을 미치는 것으로 나타났다.

• 한국산학기술학회논문지
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• 제10권10호
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• pp.2810-2818
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• 2009

본 연구는 화강풍화토로 구성된 절토사면에서 얕은파괴의 특성을 규명하고자 우리나라의 강우특성에 따른 한계투수계수를 산정하고, 국내에 분포하는 화강풍화토의 대표적 물성을 기준으로 절토사면의 파괴면까지의 수평거리, 사면의 경사각, 사면높이 그리고 강우로 인한 포화깊이 등에 따른 안정해석을 수행하여 그 결과를 분석하였다. 한계투수계수를 분석한 결과 국내의 지역별 강우특성을 고려한 최대 한계투수계수가 $7.16{\times}10^{-4}cm/sec$의 값으로 나타났다. 최대 한계투수계수 이하의 값을 갖는 국내의 화강풍화토로 구성된 절토사면에서 한계강우강도 이하의 강우가 최소 강우지속시간보다 오랫동안 지속될 때에는 포화깊이에 따른 얕은파괴의 검토가 고려되어져야 할 것으로 판단되었다. 또한, 가상파괴면이 발생하는 수평거리, 포화깊이, 강도정수 변화에 따른 사면안전율의 변화관계를 통해 절토사면의 얕은파괴 특성을 파악 할 수 있었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.273-280
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• 2001

In order to evaluate the stability of railway cut-slope under rainfall, explanatory variables and subordinate variables were selected for multivariate analysis. Furthermore the site which had occurred failure due to rainfall was investigated, and by executing multivariate analysis for 121 cases, critical rainfall was defined by the case that had high value of correlation factor. The 0.3 square value of maximum hourly rainfall during 24 hours before failure caused the collapse of railway cut-slope and could be used to estimate the stability of railway cut-slope. From the result of application to a collapse example, the evaluaton method by critical rainfall curve is satisfactory.

• 한국농공학회논문집
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• 제65권4호
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• pp.25-32
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• 2023

KDS (Korean Design Standard) for agricultural drainage is a planning standard that helps determine the appropriate capacity and type of drainage facilities. The objective of this study was to analyze the inundation of the agricultural basin considering the current design standard and the critical rainfall duration. This study used the rainfall durations of 1-48 hour, and the time distribution method with the Chicago and the modified Huff model. For the runoff model, the NRCS (Natural Resources Conservation Service) unit hydrograph method was applied, and the inundation depth and duration were analyzed using area-elevation data. From the inundation analysis using the modified Huff method with different rainfall durations, 4 hours showed the largest peak discharge, and 11 hours showed the largest inundation depth. From the comparison analysis with the current method (Chicago method with a duration of 48 hours) and the modified Huff method applying critical rainfall duration, the current method showed less peak discharge and lower inundation depth compared to the modified Huff method. From the simulation of changing values of drainage rate, the duration of 11 hours showed larger inundation depth and duration compared to the duration of 4 hours. Accordingly, the modified Huff method with the critical rainfall duration would likely be a safer design than the current method. Also, a process of choosing a design hydrograph considering the inundation depth and duration is needed to apply the critical rainfall duration. This study is expected to be helpful for the theoretical basis of the agricultural drainage design standards.

• 한국수자원학회논문집
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• 제37권9호
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• pp.695-706
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• 2004

본 연구는 실측자료가 확보된 중규모 하천유역에서 최대 첨두유량을 발생시키는 설계강우의 시간분포모형을 밝혀내고, 결정된 시간분포모형을 바탕으로 하여 유역특성과 임계지속기간의 관계를 규명하는 것이다. 50-5,000$\textrm{km}^2$의 44개 유역을 통하여 수문분석을 실시하였으며, SCS 유효우량 산정방법으로 결정된 유효우량을 사용하여 최대 첨두유량을 발생시키는 시간분포모형은 Huff의 4분위 시간분포모형으로 나타났다. 유역면적 50-600$\textrm{km}^2$인 유역에서는 24시간 강우지속기간의 첨두유량과 임계지속기간의 첨두유량은 유사한 값을 보이며, 유역면적 600-5,000$\textrm{km}^2$인 유역에서는 48시간 강우지속기간의 첨두유량과 임계지속기간의 첨두유량이 유사한 값을 보였다. AMC III 조건의 유효우량에 대하여 높은 상관성을 지니는 유역면적과 임계지속기간의 관계식을 유도하였으며, 유역면적 50-5,000$\textrm{km}^2$이 중규모 하천유역에서 임계지속기간을 결정하는데 유용한 식으로 이용될 수 있을 것으로 판단된다. 또한, 단위도 특성치를 이용한 무차원 회귀식을 유도하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.141-141
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• 2021

This study proposed an equation for Rainfall Threshold for Flood Warning (RTFW) for urban areas based on computer simulations. First, a coupled 1D-2D dual-drainage model was developed for nine watersheds in Seoul, Korea. Next, the model simulation was repeated for a total of 540 combinations of the synthetic rainfall events and watershed imperviousness (9 watersheds × 4 NRCS Curve Number (CN) values × 15 rainfall events). Then, the results of the 101 simulations with the critical flooded depth (0.25m-0.35m) were used to develop the equation that relates the value of RTFW to the rainfall event temporal variability (represented as coefficient of variation) and the watershed Curve Number. The results suggest that 1) the rainfall with greater temporal variability causes critical floods with less amount of total rainfall; and that 2) the greater imperviousness requires less rainfall to have critical floods. For validation, the proposed equation was applied for the flood warning system with two storm events occurred in 2010 and 2011 over 239 watersheds in Seoul. The results of the application showed high performance of the warning system in issuing the flood warning, with the hit, false and missed alarm rates at 68%, 32% and 7.4% respectively for the 2010 event and 49%, 51% and 10.7% for the event in 2011.

• 한국방재학회 논문집
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• 제9권1호
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• pp.135-144
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• 2009

본 연구에서는 대표단위도가 작성되어 있는 중규모 하천유역을 대상으로 첨두유량을 발생시키는 임계지속기간을 결정하고 임계지속기간과 관련된 수문요소들에 대한 평가를 수행하였다. 임계지속기간과 유역특성인자, 유역응답시간 특성인자 그리고 단위도 특성인자들과의 상관분석을 실시하였다. 분석결과, 재현기간을 제외한 나머지 수문요소(확률강우강도식, 유출량 산정방법, 유효우량 산정방법, 강우시간분포)이 임계지속기간에 영향을 미치는 것으로 판단되었다. 상관분석을 통하여 유역면적, 유로연장, 유로경사, 유역경사가 임계지속기간과 상관성이 높은 것으로 나타났다. 상관성이 높은 유역특성인자와 임계지속기간과의 다중회귀 분석을 실시하고 7가지 형태의 회귀식을 제시하였으며, 유도된 회귀식의 결정계수가 모두 $0.96{\sim}0.97$으로 나타나 매우 높은 상관관계를 갖는 것으로 나타났다.

• 한국철도학회논문집
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• 제3권4호
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• pp.203-212
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• 2000

In order to evaluate the stability of railway embankment under rainfall, explanatory variables and subordinate variables were selected for multivariate analysis. Furthermore the site which had occurred failure due to rainfall was investigated, and by executing multivariate analysis for 121 cases, critical rainfall was defined by the case that had high value of correlation factor The maximum hourly rainfall during 24 hours before failure caused the collapse of railway embankment and could be used estimate the stability of railway embankment. From the result of application to a collapse example, the evaluaton method by critical rainfall curve is satisfactory.

• 한국농공학회논문집
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• 제64권2호
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• pp.47-55
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• 2022

The objective of this study was to analyze the effect of the duration and time distribution of probability rainfall on farmland inundation for the paddy fields in the drainage improvement project site. In this study, eight drainage improvement project sites were selected for inundation modeling. Hourly rainfall data were collected, and 20- and 30-year frequency probability rainfalls were estimated for 14 different durations. Probability rainfalls were distributed using Intensity-Duration-Frequency (IDF) and Huff time distribution methods. Design floods were calculated for 48 hr and critical duration, and IDF time distribution and Huff time distribution were used for 48 hr duration and critical duration, respectively. Inundation modeling was carried out for each study district using 48 hr and critical duration rainfalls. The result showed that six of the eight districts had a larger flood discharge using the method of applying critical duration and Huff distribution. The results of inundation depth analysis showed similar trends to those of design flood calculations. However, the inundation durations showed different tendencies from the inundation depth. The IDF time distribution is a distribution in which most of the rainfall is concentrated at the beginning of rainfall, and the theoretical background is unclear. It is considered desirable to apply critical duration and Huff time distribution to agricultural production infrastructure design standards in consideration of uniformity with other design standards such as flood calculation standard guidelines.