• 한국지반공학회지:지반
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• 제7권1호
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• pp.53-68
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• 1991

이 논문은 강우가 시작된 후 시간의 경과에 따른 불구화 지반에서의 여러가지 침투거동을 밝혀서, 서면 불안정의 구체적인 머케니즘을 이해하려는데 목적이 있다. 이를 위해 강우장치를 만들어 권쬐요면에 대해 여러가지 강도의 강우를 재현하고 침투거동을 측정하는 한편, 실험에서 사용한 동일한 수치권을 가지고 수치 해석을 하였다. 두가지 모델시 험 의 결과로부터 만윤전선이 진행되는 과정,지반으로 침투되는 한계강우량의 존재,지표류출의 영향,시간의 경과에 따른 간극수압의 변화 등을 밝혀서 이들 인자들이 사면 불안정에 어떻게 영향을 끼치는가를 자세히 언급하였다.

• 물과 미래
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• 제14권4호
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• pp.27-34
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• 1981

The design flow of the urban strom drainage systems has been assessed largely on a basis of empirical relations between rainfall and runoff, and the rational formula has been widely used for the cities in our country. In order to estimate it more accurately, the urban runoff simulation model based on the RRl method has been developed and applied to the sample basin in this study. The rainfall hyetograph of the design stromfor the design flow has been obtained by the determination of the total rainfall and the temporal distributions of that rainfall. The total rainfall has been assessed from the empirical formula of rainfall intensity and the temporal distribution of that rainfall determined on the basis of Huff's method from the historical rainfall data of the basin. The virtual inflow hydrograph to each inlet of the basin has been constructed by computing the series of discharges in each time increment, using design strom hyetograph and time-area diagram. The actual runoff hydrograph at the basin outlet has been computed from the virtual inflow hydrographs by developing a relations between discharge and storage for the watershed. The discharge data for verification of the simulated runoff hydrograph are not available in the sample basin and so the sensitivity analysis of the simulation model has not been possible. The peak discharge for the design of drainage systems has been estimated from the computed runoff hydrograph at the basin outlet and compared to thatl obtained form the rational formula.

• 상하수도학회지
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• 제23권5호
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• pp.599-608
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• 2009

This manuscript covers the results of field investigation and lab-scale experiments to design a double-layered biofilter system to control urban storm runoff. The biofilter system consisted of a coarse soil layer (CSL) for filtration and fine soil layer (FSL) for adsorption and biological degradation. The variations of flow rate and water quality of runoff from a local expressway were monitored for seven storm events. Laboratory column experiments were performed using seven kinds of soil and mulch to maximize pollutants removal. The site mean concentration (SMC) of storm runoff from the drainage area (runoff coefficient: 0.92) was measured to be 203 mg/L for SS, 307 mg/L for $TCOD_{Cr}$, 12.3 mg/L for TN, 7.3 mg/L for ${NH_4}^+-N$, and 0.79 mg/L for TP, respectively. This study employed a new design concept, to cover the maximum rainfall intensity with one month recurrence interval. Effective storms for last ten years (1998-2007) in seoul suggested the design rainfull intensity to be 8.8 mm/hr Single layer soil column showed the maximum removal rate of pollutants load when the uniformity coefficient of CSL was 1.58 and the silt/clay contents of FSL was virtually 7%. The removal efficiency during operation of double layer soil column was 98% for SS and turbidity, 75% for TCODCr, 56% for ${NH_4}^+-N$, 87% for TP, and 73-91% for heavy metals. The hydraulic conductivity of the soil column, 0.023 cm/sec, suggested that the surface area of the biofilter system should be about 1% of the drainage area to treat the rainfall intensity of one month recurrence interval.

• 한국수자원학회논문집
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• 제46권5호
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• pp.559-568
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• 2013

토양의 다짐은 강우 시 지표유출 및 토사유출에 큰 영향을 끼친다. 다짐은 체적밀도 증가, 전단강도 증가, 공극률 변형, 투수계수 등과 같은 토양특성 변화를 야기하기 때문이다. 본 연구는 인공강우 실험을 활용하여 개발지의 사면조건과 유사한 나지교란사면에서 표면의 다짐처리가 지표유출 및 토사유출에 미치는 영향을 파악하였다. 표면처리(다짐, 비다짐), 강우강도(68.5mm/hr, 95.6mm/hr), 사면경사($5^{\circ}$, $12.5^{\circ}$, $20^{\circ}$)의 각 조건별 3회 반복하여 총 36회의 강우모의에 따른 지표유출 및 토사유출을 측정하였다. 연구결과, 다짐처리 후 토양의 체적밀도 및 전단강도는 유의적으로 증가하였다. 그러나 이러한 물리적 특성의 변화가 지표유출에 미치는 영향은 강우강도와 사면경사에 따라 다르게 반응하였다. 평균 토사유출량은 강우강도와 사면경사가 증가함에 따라 유의적으로 증가하였다. 또한, 토사유출량은 강우강도와 사면경사 별 다짐처리 유 무에 따라 다른 반응을 보였다. 완경사($5^{\circ}$)에서는 다짐처리에서 더 많은 토사가 유출되었으나, 급경사($20^{\circ}$)에서의 다짐처리는 토사유출을 감소시키는 역할을 한 것으로 나타났다. 나지교란사면에서는 토사유출에 대한 다짐효과의 천이구간이 존재하는 것으로 파악되며, 본 연구의토양조건 및 강우조건에서 천이구간은 완경사와 급경사 사이로서 사면경사 $10{\sim}15^{\circ}$ 범위에 존재하는 것으로 판단된다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1998년도 학술발표회 논문집
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• pp.103-108
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• 1998

• Geomechanics and Engineering
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• 제17권1호
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• pp.109-118
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• 2019

The movement of soil along a slope during rainfall can cause serious economic damage and can jeopardize human life. Accordingly, predicting slope stability during rainfall is a major issue in geotechnical engineering. Due to rainwater penetrating the soil, the negative pore water pressure will decrease, in turn causing a loss of shear strength in the soil and ultimately slope failure. More seriously, many constructions such as houses and transmission towers built in/on slopes are at risk when the slopes fail. In this study, the numerical simulation using 2D finite difference program, which can solve a fully coupled hydromechanical problems, was used to evaluate the effects of soil properties, rainfall conditions, and the location of a foundation on the slope instability and slope failure mechanisms during rainfall. A slope with a transmission tower located in Namyangju, South Korea was analyzed in this study. The results showed that the correlation between permeability and rainfall intensity had an important role in changing the pore water pressure via controlling the infiltrated rainwater. The foundation of the transmission tower was stable during rainfall because the slope failure was estimated to occur at the toe of the slope, and did not go through the foundation.

• 대한토목학회논문집
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• 제28권4B호
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• pp.363-374
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• 2008

국내에서 수공구조물의 설계를 위한 확률강우량을 산정하기 위해서 널리 사용되는 강우강도식은 주로 회귀분석을 적용한 형태가 일반적이지만, 본 연구에서는 각 지점별 적정확률분포형의 누가분포함수를 활용하여 강우강도식의 형태를 결정하고, 매개변수는 유전자알고리즘을 적용하여 추정하는 강우강도식을 제안하고자 한다. 기존에 사용하던 강우강도식과의 정확도 비교를 위하여 기상청 22개 지점에 대한 재현기간, 지속기간별 평균제곱근오차, 평균제곱근 상대오차를 검토한 결과 누가분포함수를 활용한 강우강도식이 더 높은 정확도를 가짐을 보였으며, 또한, 최근의 집중호우에 대한 영향을 살펴보기 위하여 2006년 까지의 강우자료를 이용하여 기존의 회귀식에 의한 방법과 누가분포함수를 활용한 경우의 결과값을 비교한 결과 이 경우에도 누가분포함수를 활용한 강우강도식의 정확도가 더 높음을 알 수 있었다. 결과적으로 본 연구에서 제안된 누가분포함수를 활용한 강우강도식은 기존의 회귀분석을 활용한 강우강도식보다 정확도면에서 우수하다고 할 수 있으며, 국내에 충분히 적용가능한 형태의 강우강도식이라고 판단된다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.424-424
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• 2017

Several studies of the world have analyzed the regional rainfall trends in large data sets. However, it reported that the long-term behavior of rainfall was different on spatial and temporal scales. The objective of this study is to determine the local trends of rainfall indices in the Yom River Basin, Thailand. The rainfall indices consist of the annual total precipitation (PRCTPOP), number of heavy rainfall days ($R_{10}$), number of very heavy rainfall days ($R_{20}$), consecutive of dry days (CDD), consecutive of wet days (CWD), daily maximum rainfall ($R_{x1}$), five-days maximum rainfall ($R_{x5}$), and total of annual rainy day ($R_{annual}$). The rainfall data from twelve hydrological stations during the period 1965-2015 were used to analysis rainfall trend. The Mann-Kendall test, which is non-parametric test was adopted to detect trend at 95 percent confident level. The results of these data were found that there is only one station an increasing significantly trend in PRCTPOP index. CWD, which the index is expresses longest annual wet days, was exhibited significant negative trend in three locations. Meanwhile, the significant positive trend of CDD that represents longest annual dry spell was exhibited four locations. Three out of thirteen stations had significant decreasing trend in $R_{annual}$ index. In contrast, there is a station statistically significant increasing trend. The analysis of $R_{x1}$ was showed a station significant decreasing trend at located in the middle of basin, while the $R_{x5}$ of the most locations an insignificant decreasing trend. The heavy rainfall index indicated significant decreasing trend in two rainfall stations, whereas was not notice the increase or decrease trends in very heavy rainfall index. The results of this study suggest that the trend signal in the Yom River Basin in the half twentieth century showed the decreasing tendency in both of intensity and frequency of rainfall.

• 한국수자원학회논문집
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• 제51권3호
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• pp.221-233
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• 2018

최근 기후변화로 인한 국지성 호우 및 태풍 피해가 자주 발생하고 있다. 이와 같은 피해를 저감하기 위해서는 정확한 강우의 예측과 홍수량 산정이 필요하다. 그러나 지점 및 레이더 강우 시 공간적 오차를 포함하고 있고, 유출 모형에 의한 유출수문곡선 역시 보정을 실시하더라도 관측유량과 오차를 가지고 있어 불확실성이 존재한다. 따라서 본 연구에서는 확률론적 강우 앙상블을 생성하여 강우의 불확실성을 확인하였다. 또한 유출 결과를 통해 수문 모형의 불확실성을 확인하였고, 블랜딩 기법을 이용하여 하나의 통합된 유출 수문곡선을 제시하였다. 생성된 강우앙상블은 강우강도 및 지형적인 영향으로 레이더가 과소 관측이 될 때, 강우 앙상블의 불확실성이 큰 것을 확인하였고, 블랜딩 기법을 적용하여 산정된 최적 유출 수문곡선은 유출모형의 불확실성을 크게 줄이는 것으로 나타났다. 본 연구 결과를 활용한다면, 정확한 홍수량 산정 및 예측을 통해 집중호우로 인한 피해를 줄일 수 있을 것으로 판단된다.

• 한국농공학회지
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• 제24권1호
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• pp.63-72
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• 1982

To maintain an optimum condition for the plant growth on upland soil, the irrigation planning after the natural rainfall should be given enormous considerations on the rainfall effectiveness. This study has been intended to develop the computer model for estimating the effec- tiveness of the rainfall. The computer model should also estimated the infiltration due to the rainfall and the soil moisture deficiency at the root zone of the plant. For this purpose, the experiments of infiltration using rainfall simulator and the observations of the change of soil moisture content before and after rainfall were carried out. Needed input data for the developed model include final infiltration capacity and field capacity of the soil, porosity of the top soil, root depth of the plant, rainfall intensity and duration, and the Horton's decay coefficient. Among the needed input data for the developed model, final infiltration capacity and Horton's decay coefficient were determined by the experiments of infiltration. And from the result of the experiments, it is found that there is a great correlation between initial infiltration capacity and initial moisture content. And it is also found that the infiltration due to rainfall can be estimated with the Horton's equation. The developed model was tested by the experimental data with two rainfall intensities. Tests were conducted on the different root depths at each rainfall. Observed and estimated effective rainfalls were found to have great correlation. The result of the experiments showed that the effectiveness of the rainfall were 100%, so the comparisons were conducted by the comsumption rates of infiltration at each depth. The developed model can be also used for estimating the deficiency of rainfall, if the rainfall is not sufficient to the needed soil moisture. But, test was not carried out.