• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.1558-1562
• /
• 2007

우리나라 지형은 전체의 70%가 산지로 이루어져 있다. 특히 강원도 지역과 같이 산지가 대부분인 지역에서는 경사도에 따라 강우에 의한 유출특성이 크게 달라질 수 있으므로 지형의 경사가 고려된 유출량 산정방식이 필요하다. 현재 유출량 산정 방식에 많이 이용되고 있는 SCS의 CN값은 미국의 중서부 지역과 같이 경사도 5%미만인 지역에서의 유출량 산정에 적합한 유출곡선지수이다. 경사도 5%에서 유출량 산정에 적합한 CN값을 우리나라의 강원도 지형과 같이 복잡하고 경사도가 심한 지역에 적용하기에는 부적합하다. 따라서 본 연구에서는 연구대상지역인 도암댐 유역의 평균 25.8% 경사도를 고려한 직접유출량을 산정하여 기존 평균 경사도 5%일 때의 직접유출량과 비교분석하였다. 본 연구의 비교분석에 있어서 직접유출의 모의가 가능한 Long-Term Hydrologic Impact Assessment (L-THIA) ArcView GIS 모델을 사용하였고 모델의 적용성 평가를 위해 수문분석에 사용되고 있는 WHAT 모듈을 이용하여 분리된 직접유출과 비교하였다. 그 결과 유출량 산정을 위해 CN값 산정시 강원도 지형과 같이 지형이 복잡하고 경사가 심한 지형에 있어서는 유역의 경사도를 고려하여 유출을 모의해야 한다는 것을 알 수 있다.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2001.10a
• /
• pp.110-110
• /
• 2001

• Journal of Korea Water Resources Association
• /
• v.52 no.3
• /
• pp.219-226
• /
• 2019

Recently, research about Low-Impact Development (LID) techniques has been expanded due to problems with the effects of climate change and urbanization that have been increasing. LID technology is used to control flood damage environmentally to reduce runoff and is reduce runoff on city also restore into previous water circulation system from present developed city. However, studies about quantitative data of LID techniques are insufficient. Therefore in this study, the Curve Number (CN) was calculated with the Planter Box, which is storage type LID technology to conduct the water circulation (infiltration, runoff, overflow) analysis. Rainfall intensity scenario (60.4 mm/hr, 83.1 mm/hr, 97.4 mm/hr, 108.2 mm/hr) about water circulation analysis of Planter Box is selected on the basis of probable rainfall intensity table. According to the experimental results, the storage rate of rainwater in Building Planter Box and Street Planter Box was 43.5% to 52.9% and 33.4% to 39%, respectively. In addition, CN value is estimated to 83 at the Planter box and the runoff reduction effect by applying Horton's infiltration capacity curve showed on 51% to 98%.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.47 no.3
• /
• pp.59-68
• /
• 2005

The rainfall-runoff potential of Jangseong reservoir watershed was studied based on SCS (Soil Conservation Service, which is now the NRCS, Natural Resources Conservation Service, USDA) runoff curve number (CN) technique. Precipitation and reservoir operation data had been collected. The rainfall-runoff pairs from the watershed for ten years was estimated using reservoir water balance analysis using reservoir operation records. The maximum retention, S, for each storm event from rainfall-runoff pair was estimated for selected storm events. The estimated S values were arranged in descending order, then its probability distribution was determined as log-normal distribution, and associated CNs were found about probability levels of Pr=0.1, 0.5, and 0.9, respectively. A subwatershed that has the similar portions of land use categories to the whole watershed of Jangseong reservoir was selected and hydrologic monitoring was conducted. CNs for subwatershed were determined using observed data. CNs determined from observed rainfall-runoff data and reservoir water balance analysis were compared to the suggested CNs by the method of SCS-NEH4. The $CN_{II}$ measured and estimated from water balance analysis in this study were 78.0 and 78.1, respectively. However, the $CN_{II}$, which was determined based on hydrologic soil group, land use, was 67.2 indicating that actual runoff potential of Jangseong reservoir watershed is higher than that evaluated by SCS-NEH4 method. The results showed that watershed runoff potential for large scale agricultural reservoirs needs to be examined for efficient management of water resources and flood prevention.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2017.05a
• /
• pp.215-215
• /
• 2017

NRCS-CN 방법은 총 강우량으로부터 유출량을 계산하는 방법으로, 국내에서는 설계홍수량 산정 시 NRCS-CN 방법의 사용을 권장하고 있다. CN값은 토지이용 및 피복, 토양특성, 수문학적 조건(AMC)에 따른 함수로 결정할 수 있으나, 보통의 경우 미국의 National Engineering Handbook (NEH-4)에서 제시한 표를 활용한다. 그러나, 우리나라의 토지피복 및 토지이용 현황은 미국과 다르기 때문에 현실 조건을 반영한 조정이 필요함에도 불구하고, 충분한 관측 자료가 확보되지 않아 이러한 조정이 어려운 실정이다. NRCS-CN 방법에서는 결과 값이 총 강수량보다 CN에 크게 의존적이기 때문에 부정확한 CN 값의 산정은 큰 오차를 야기할 수 있다. 또한 소유역에서는 초기손실량이 설계홍수량 산정에 큰 영향을 미치지만 우리나라는 초기손실률을 20%의 고정된 값을 일괄적으로 적용하고 있으며, 이는 제주도와 같은 특수한 투수성 지층에서는 적합하지 않다는 지적을 받아왔다. 여러 선행연구에서 강수량과 CN 사이에는 특정 관계식이 존재하며, 고정된 CN 값이 아닌 강수량에 따라 변화하는 값을 적용하는 것이 기존의 NRCS-CN 방법보다 더 정확한 결과를 나타낸다는 것이 확인된 바 있다. 본 연구에서는 NRCS-CN 방법의 CN 값과 초기손실률을 유역에 적합하게 개선하기 위해서 기존의 NRCS-CN 모형에 점근 유출곡선지수방법(Asymptotic CN Regression Method)을 통해 산정된 CN값과 각기 다른 초기손실률(0.01, 0.05, 0.10, 0.20, 0.40)을 적용하여 개선된 총 8개의 모형을 한강 권역 소유역에 적용하였다. RMSE, MAE 및 R-square 등의 지표를 이용하여 모형 검정을 수행하였으며, 최적의 모형 및 미개변수를 선정하였다. 그 결과 기존의 NRCS-CN 방법보다 점근 유출곡선지수방법을 적용했을 때 더 작은 오차를 나타내는 것을 확인하였으며, 대부분의 유역에서 0.01 또는 0.05 등 기존보다 더 작은 초기손실률을 채택 시 실측값과 가장 적은 오차를 나타냈다.

• Journal of Korea Water Resources Association
• /
• v.38 no.11
• /
• pp.955-962
• /
• 2005

Even though the runoff volume is very sensitive to the antecedent soil moisture condition (AMC), the general rainfall-runoff analysis in Korea has accepted, without careful consideration of its applicability, the AMC classification of the Soil Conservation Service (SCS, 1972). In this study, by following the development procedure of SCS Curve Number (CN), the rainfall-runoff characteristics of the Jangpyung subbasin of the Pyungchang River Basin were analyzed to estimate the CN and evaluate the AMC classification of currently being used. As results, CN(I), CN(II), and CN(III) were estimated to be 72.1, 79.3, and 76.7, respectively. Among them CN(II) was found to be similar to the other reports but the other two were totally different from those of theoretically estimated. However, it is difficult to evaluate the AMC with CN, rather the frequency of each AMC could be a better indicator for its validity. This study developed the histogram of AMC and compared the frequency of each AMC. hs results we found that the criterion for AMC-III should be increased, Hut that for AMC-I decreased.

• Genomics & Informatics
• /
• v.20 no.1
• /
• pp.4.1-4.8
• /
• 2022

Loss of heterozygosity (LOH) is a genomic aberration. In some cases, LOH can be generated without changing the copy number, which is called copy-neutral LOH (CN-LOH). CN-LOH frequently occurs in various human diseases, including cancer. However, the biological and clinical implications of CN-LOH for human diseases have not been well studied. In this study, we compared the performance of CN-LOH determination using three commonly used tools. For an objective comparison, we analyzed CN-LOH profiles from single-nucleotide polymorphism array data from 10 colon adenocarcinoma patients, which were used as the reference for comparison with the CN-LOHs obtained through whole-exome sequencing (WES) data of the same patients using three different analysis tools (FACETS, Nexus, and Sequenza). The majority of the CN-LOHs identified from the WES data were consistent with the reference data. However, some of the CN-LOHs identified from the WES data were not consistent between the three tools, and the consistency with the reference CN-LOH profile was also different. The Jaccard index of the CN-LOHs using FACETS (0.84 ± 0.29; mean value, 0.73) was significantly higher than that of Nexus (0.55 ± 0.29; mean value, 0.50; p = 0.02) or Sequenza (0 ± 0.41; mean value, 0.34; p = 0.04). FACETS showed the highest area under the curve value. Taken together, of the three CN-LOH analysis tools, FACETS showed the best performance in identifying CN-LOHs from The Cancer Genome Atlas colon adenocarcinoma WES data. Our results will be helpful in exploring the biological or clinical implications of CN-LOH for human diseases.

• Journal of Korea Water Resources Association
• /
• v.50 no.11
• /
• pp.759-767
• /
• 2017

Two main parameters of NRCS-CN method are curve numbers and intial loss ratio. They are generally selected according to the guideline of US National Engineering Handbook, however, they might cause errors on estimated runoff in Korea because there are differences between soil types and hydrological characteristics of Korean watersheds and those of United States. In this study, applying asymptotic CN regression method, we suggested eight modified NRCS-CN models to decide optimum runoff estimation model for Korean watersheds. RSR (RMSE-observations standard deviation ratio) and NSE (Nash-Sutcliffe efficiency) were used to evaluate model performance, consequently M6 for gauged basins (Avg. RSR was 0.76, Avg. NSE was 0.39) and M7 for ungauged basins (Avg. RSR was 0.82, Avg. NSE was 0.31) were selected. Furthermore it was observed that initial loss ratios ranging from 0.01 to 0.10 were more adequate than the fixed ${\lambda}=0.20$ in most of basins.

• Journal of Wetlands Research
• /
• v.15 no.4
• /
• pp.609-618
• /
• 2013

Curve number (CN), originally developed, compiled by 'The Natural Resources Conservation Service (NRCS)', and has been widely used throughout the world. However, there is the uncertainty of CN derived from the use of antecedent moisture condition (AMC)/Antecedent Runoff Condition (ARC). As in Korea where nearly 70% covered by mountainous area, it is still not sufficient handbook precedent to guide or support the estimation of AMC/ARC. The failure to develop formal criteria of applying AMC/ ARC will be a gaping profession and results not only in uncertainty of CN estimation in particular, but also in designing appropriate structures in Korea as a whole. This paper is aiming at presenting a critical review of AMC/ARC and deriving a procedure to deal more realistically with event rainfall-runoff over wider variety of initial conditions. Proposed methods have been developed. It is based on modifying estimated runoff to observed runoff with coefficient of determination and then applying different algebraic expression with the verification of AMC by antecedent rainfall table of NEH-1964. The result shows that algebraic expression by Arnold et al. (1996) is the most appropriate for AMC/ARC and the results of AMC/ARC estimation criteria are generally very close to each other. Therefore, this algebraic expression might be applied in South Korea condition properly.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.53 no.5
• /
• pp.9-16
• /
• 2011

Curve Numbers (CN) for the combination of land use and hydrologic soil group were regionalized at Imha Watershed using Long-term Hydrologic Impact Assessment (L-THIA) coupled with SCE-UA. The L-THIA was calibrated during 1991-2000 and validated during 2001-2007 using monthly observed direct runoff data. The Nash-Sutcliffe (NS) coefficients for calibration and validation were 0.91 and 0.93, respectively, and showed high model efficiency. Based on the criteria of model calibration, both calibration and validation represented 'very good' fit with observe data. The spatial distribution of direct surface runoff by L-THIA represented runoff from Thiessen pologen at Subi and Sukbo rain gage station much higher than other area due to the combination of poor hydrologic condition (hydrologic soil C and D group) and locality heavy rainfall. As a results of hydrologic condition and treatment for land use type based on calibrated CNs, forest is recommended to be hydrologically modelled dived into deciduous, coniferous, and mixed forest due to the hydrological difference. The CNs for forest and upland showed the poor hydrologic condition. The steep slope of forest and alpine agricultural field make high runoff rate which is the poor hydrologic condition because CN method can not consider field slope. L-THIA linded with SCE-UA could generated a regionalized CNs for land use type with minimized time and effort, and maximized model's accuracy.