• 상하수도학회지
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• 제24권5호
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• pp.509-517
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• 2010

Statistical distribution of annual maximum rainfall intensity of 18 cities in Korea was analyzed and applied to the reliability model which can calculate the probability of performance failure of storm sewer. After the analysis, it was found that distribution of annual maximum rainfall intensity of 18 cities in Korea is well matched with Gumbel distribution. Rational equation was used to estimate the load and Manning's equation was used to estimate the capacity in reliability function to calculate the probability of performance failure of storm sewer. Reliability analysis was performed by developed model applying to the real storm sewer. It was found that probability of performance failure is abruptly increased if the diameter is smaller than certain size. Therefore, cleaning the inside of storm sewer to maintain the original diameter can be one of the best ways to reduce the probability of performance failure. In the present study, probability of performance failure according to accumulation of debris in storm sewer was calculated. It was found that increasing the amount of debris seriously decrease the capacity of storm sewer and significantly increase the probability of performance failure.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.192-199
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• 2010

This research produced internal model tester ($2.0m{\times}2.0m{\times}1.0m$) to evaluate the field application of Paju Unjeong District water recycling system for small streams eco-friendly river bed disparity method for the first time in Korea and conducted comparative analysis of the Paju Unjeong District water recycling system field test results and infiltration rate result of internal tests by each rainfall intensity following surface material. Infiltration rate result of internal tests concrete pavement by rainfall intensity following surface material, asphalt pavement, bentonite mate, stabilized soil construction and mixed soil construction manifested low infiltration rate. On the contrary, compaction soil, grassland and water permeable packaging materials resulted in significant amount of infiltration rate. As for the field permeability test results, they were manifested similar tendency as indoor permeability test results and they satisfied the standard for standard of water permeability of domestic disparity facility (less than $1.0{\times}10-7cm$/sec). As compaction rate increased, unconfined compression strength increased as well while coefficient of water permeability decreased.

• 한국도로학회논문집
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• 제19권6호
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• pp.147-153
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• 2017

PURPOSES : This research aims to estimate the occurrence of hydroplaning on roads based on the road alignment types and rainfall intensity in Seoul. METHODS : Three types of data were used for estimation of hydroplaning in this study. The Inner Circulation Road (12.5 km) to the Bukbu Expressway (7.4 km) in Seoul was selected as the test road and data was collected for road information using a probe-vehicle. Precipitation was observed from Automatic Weather System in Seoul. These data were interpolated by applying Inverse Distance Weighted Methodology for hydroplaning estimation. Finally, the water depth information of the roads was observed using an RCM411 device. RESULTS : This study demonstrated that the cross slope with small-angle-tilt or vertical section with large-angle-tilt are the primary factors causing hydroplaning on the roads. The flow velocity on steep slope is high; however, large drainage lengths result in hydroplaning on the roads. CONCLUSIONS : This result can contribute towards the reduction of car accidents on rainy days. Furthermore, information regarding hydroplaning can be delivered to drivers more rapidly and precisely in the future.

• 지질공학
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• 제28권4호
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• pp.687-699
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• 2018

강우변화에 따라 토층 내로 침투되는 강우양상을 파악하는 것은 산사태 위험도 평가에 있어 매우 중요한 요소라 할 수 있다. 본 연구에서는 재현기간 별 강우변화에 따른 안전율 기반의 산사태 위험도를 평가하고 이를 바탕으로 연구지역 내 산사태 위험지수를 제안하고자 하였다. 산사태 위험지수는 토층으로 침투되는 강우양상을 침투깊이비로 추정하고 이를 기반으로 산사태 위험도를 사전에 파악할 수 있도록 지수로 표현한 것이다. 연구지역에 대한 산사태 위험도 분석결과, 빈도 별 강우강도가 증가하면서 연구지역 전체 안전율은 감소하는 경향을 보였으나 50년 빈도 이상의 강우조건에서는 점차 수렴하는 경향을 보였다. 이러한 현상은 침투깊이비와 토층깊이에서도 유사하게 나타났으며 경사가 완만할수록 침투깊이가 깊은 것으로 분석되었다. 분석결과를 바탕으로 연구지역 내 복수의 산사태가 발생된 인후리 지역에 대하여 산사태위험지수를 제안하였다. 제안된 산사태위험지수는 과거 산사태 발생 시 강우조건과 비교, 분석한 결과 대부분의 산사태 발생 강우강도 조건에서는 산사태위험지수 2등급, 0.7이상에서 발생된 것으로 분석되었다.

• 한국물환경학회지
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• 제24권1호
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• pp.69-77
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• 2008

This study was conducted to know the characteristics of agricultural non-point source pollutants runoff by rainfall events at the upper catchment of Goseong reservoir in Gonjy city, Chungnam Province. For this study, the monitoring sites of the research catchment were set nineteen during the research period (between June 2005 and October 2006). Average runoff coefficient were observed 0.51 in 2005, 0.71 in 2006, respectively. The correlation coefficient (r) between the rainfall and peak-flow was investigated 0.787. By rainfall events, the water quality of the sites were shown like this : BOD 0.555~9.60 mg/L, T-N 0.01~13.50 mg/L, T-P 0.002~2.952 mg/L, and SS N.D~820.0 mg/L. The strong rainfall intensity was the most important factor of the soil erosion. The gabs of the arithmetic mean concentrations and the flow weighted mean concentrations were observed as the followings : BOD 0.0~29.2%, T-N 0.1~11.4%, T-P 0.4~95.2%, and SS 1.7~57.0% in 2005, and BOD 1.0~11.9%, T-N 0.7~7.3%, T-P 9.9~36.5%, and SS 6.6~36.5% in 2006, respectively. The BOD pollution load was 2,117 kg (36% of the total BOD loading of survey periods) while, T-N was 3,209.0 kg (27.9% of the total T-N loading of survey periods), T-P was 136.4 kg (37.4% of the total T-P loading of survey periods) and SS was 72,733.8 kg (51.8% of the total SS loading of survey periods) in the year 2005. In case of 2006, BOD load was 1,321.7, T-N was 2,845.8, T-P was 42.9, and SS was 16,275.8 kg, respectively.

• 한국토양비료학회지
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• 제45권1호
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• pp.112-117
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• 2012

The Revised Universal Soil Loss Equation (RUSLE) is a revision of the Universal Soil Loss Equation (USLE). However, changes for each factor of the USLE have been made in RUSLE which can be used to compute soil loss on areas only where significant overland flow occurs. RUSLE which requires standardized methods to satisfy new data requirements estimates soil movement at a particular site by utilizing the same factorial approach employed by the USLE. The rainfall erosivity in the RUSLE expressed through the R-factor to quantify the effect of raindrop impact and to reflect the amount and rate of runoff likely is associated with the rain. Calculating the R-factor value in the RUSLE equation to predict the related soil loss may be possible to analyse the variability of rainfall erosivity with long time-series of concerned rainfall data. However, daily time step models cannot return proper estimates when run on other specific rainfall patters such as storm and daily cumulative precipitation. Therefore, it is desirable that cross-checking is carried out amongst different time-aggregations typical rainfall event may cause error in estimating the potential soil loss in definite conditions.

• Journal of Animal Science and Technology
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• 제65권4호
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• pp.792-803
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• 2023

This study aimed to assess the impact of weather events on the sorghum-sudangrass hybrid (Sorghum bicolor L.) cultivar production trend in the central inland region of Korea during the monsoon season, using time series analysis. The sorghum-sudangrass production data collected between 1988 and 2013 were compiled along with the production year's weather data. The growing degree days (GDD), accumulated rainfall, and sunshine duration were used to assess their impacts on forage production (kg/ha) trend. Conversely, GDD and accumulated rainfall had positive and negative effects on the trend of forage production, respectively. Meanwhile, weather events such as heavy rainfall and typhoon were also collected based on weather warnings as weather events in the Korean monsoon season. The impact of weather events did not affect forage production, even with the increasing frequency and intensity of heavy rainfall. Therefore, the trend of forage production for the sorghum-sudangrass hybrid was forecasted to slightly increase until 2045. The predicted forage production in 2045 will be 14,926 ± 6,657 kg/ha. It is likely that the damage by heavy rainfall and typhoons can be reduced through more frequent harvest against short-term single damage and a deeper extension of the root system against soil erosion and lodging. Therefore, in an environment that is rapidly changing due to climate change and extreme/abnormal weather, the cultivation of the sorghum-sudangrass hybrid would be advantageous in securing stable and robust forage production. Through this study, we propose the cultivation of sorghum-sudangrass hybrid as one of the alternative summer forage options to achieve stable forage production during the dynamically changing monsoon, in spite of rather lower nutrient value than that of maize (Zea mays L.).

• 한국토양비료학회지
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• 제49권2호
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• pp.218-225
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• 2016

This experiment was conducted in Suwon and Iksan city from 2012 to 2014 to evaluate soil erosion and nutrient loss from irrigated paddy fields during cropping period. Rainfall amount and rainfall erosivity of $EI_{30}$ were, on average, 1,026 mm and $3,922mm\;ha^{-1}yr^{-1}hr^{-1}$ for the cropping period, respectively, and the rainfall event with maximum $EI_{30}$ occurred in July. Annual average of runoff was $2,508MT\;ha^{-1}yr^{-1}$ in Suwon and $3,375MT\;ha^{-1}yr^{-1}$ in Iksan, accounting for 36% of rainfall of the cropping period. Nutrient loss by runoff, on average, was $7.0kg\;N\;ha^{-1}yr^{-1}$, $1.3kg\;P\;ha^{-1}yr^{-1}$, and $16.6kg\;K\;ha^{-1}yr^{-1}$; N, P, and K loss were 5.0, 0.6, and $8.3kg\;ha^{-1}yr^{-1}$, respectively, in Suwon and 8.9, 1.9, and $16.7kg\;ha^{-1}yr^{-1}$ in Iksan. Soil loss in Korean paddy rice was evaluated as $0.33MT\;ha^{-1}yr^{-1}$ ranging from $0.05MT\;ha^{-1}yr^{-1}$ to $0.88MT\;ha^{-1}yr^{-1}$. Amount of soil loss, however, depended on areas and year influenced by variation of rainfall amount and intensity. Interestingly, soil erosion in Iksan in 2012 was remarkably greater than those in other periods due to heavy rainfall between late May and June with soil flake dispersion right after the rice-planting season.

• 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.

• 대한지리학회지
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• 제41권6호
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• pp.670-681
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• 2006

본 연구는 산림이 잘 보존되고 있는 경기도 구리시 동구릉 지역 내의 완사면 곡두부 지점에서의 호우시 지중수 유출과 지형형성 프로세스를 규명하고자 실시되었다. 본 연구 결과 'U자골' 곡두부의 경우 20mm 이하의 강우시에는 지하수위 변화가 거의 없었으나 곡두사면과 그 상부 지점에서는 총강우량과 강우강도에 의해서 지하수위가 크게 변화하고 있는 것으로 나타났으며, 그 변동 폭은 선행강우량과 그 경과시간, 그리고 강우지속시간과 밀접한 관계가 있는 것으로 확인되었다. 이러한 현상에 영향을 미치는 요인으로는 강우시 형성된 사면의 유출특성, 즉 지하수위 상승에 기인한 복귀류 발생과 'U자골' 곡두사면을 따라 빠르게 흐르는 측방류를 들 수 있으며 이러한 지중수의 흐름은 'U자골' 지형발달에 중대한 영향을 미친다. 사면 곡두부 지형은 지중수에 의해 변형되고 있음을 알 수 있다.