• Korean Journal of Environmental Agriculture
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• v.19 no.5
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• pp.419-425
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• 2000

Rating curve method and SWMM (Storm Water Management Model) were applied to estimate pollutant loading from Hwa-Ong watershed in Kyunggi-Do. Rating curves were derived from sampling sites and applied to the whole watershed. SWMM version 4.4 was calibrated by field data of sampling sites and applied to the whole watershed. The pollutant loading estimated by rating curve was slightly higher than the one by SWMM, but the difference was not significant considering diffuse pollution characteristics of wide variation. Land use effect of the subcatchments could not be incorporated logically in rating curve method and difficulty in extrapolation was experienced, therefore, the estimate by rating curve method was thought to be less confident. SWMM was satisfactory in estimation of pollution loading, and its great flexibility worked well to describe complex nonurban land uses. Neither of them could exactly describe complex natural phenomena, but SWMM was preferred in this study due to its flexibility and logical hydrologic processes including land use effects. Use of reasonable watershed model rather than rating curve method for watershed pollutant loading estimate can be more practical and is recommended.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.679-683
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• 2005

The technique which connects Generalized Regression Neural Networks Model(GRNNM) with Genetic Algorithm (CA) is used to derive rating curve in the river basin. GRNNM architecture consists of 4 layers ; input, hidden, summation and output layer. GA method is applied to estimate the optimal smoothing factor when GRNNM is trained. The derivation of rating curve using GRNNM is considered different kinds of hydraulic characteristics such as water stage, area and mean velocity and is applied two stage stations; Sunsan and Jungam. Furthermore, it is compared with conventional curve-fitting method. Through the training and validation performance, the results show that GRNNM is much superior as compared to the conventional curve-fitting method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.291-294
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• 2005

In this study, we compared and analyzed the floor impact sound insulation performance produced by the rating methods. The rating methods are using reversed A-weighting curve, A-weighted sound pressure levels and arithmetic average. On-site floor impact sound pressure levels of living room and room are measured. The results of this study are 1)the rating using reversed A-weighting curve for heavy-weight impact sound's standard deviation is lower than that of light-weight impact sound, 2)the number of rating using A-weighted sound pressure levels and arithmetic average is larger than that of using reversed A-weighting curve, and 3)the number of rating using reversed A-weighting curve mainly depends on impact sound pressure level of 63Hz in heavy-weight impact sound.

• Journal of Environmental Science International
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• v.13 no.9
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• pp.759-765
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• 2004

HEC-RAS model is used for estimation of rating-curve of Musung in Wi stream. Discharge is computed from stage estimated by HEC-RAS model, is compared with the discharge of water surface slope method. The relative deviation of observed and computed discharge is 5.37%, and shows as a good results. A rating-curve by HEC-RAS model shows better results than by water surface slope method.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.483-483
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• 2023

2020년 8월 섬진강 유역에서 100년 빈도 이상의 대홍수가 발생함에 따라 제방이 붕괴되거나 하천 범람이 발생하는 피해가 발생하였다. 8월 홍수를 대상으로 섬진강 본류 남원(신덕리) 수위국에서 기존의 수위-유량 관계 곡선식(이하 Rating curve)의 최대 적용 가능 수위는 2.53m 이지만, 해당 기간 첨두 수위는 10m 이상을 기록하였다. 이러한 대홍수의 경우 기왕의 관측데이터가 없을 뿐만 아니라 기존의 Rating curve를 외삽하여 활용하는 것에도 한계가 있어 간접적으로 유량을 산정할 수 있는 기법이 필요하다. 본 연구에서는 이와 같이 유량측정이 어려운 지점을 대상으로 주어진 유량에 대하여 수위를 재현할 수 있는 K-water에서 개발된 K-River모형(1차원 하천수리해석모형)과 Monte Carlo 시뮬레이션 기법을 활용하여 간접적으로 유량을 산정할 수 있는 기법을 개발하였다. 개발된 방법론은 고수위 구간에 대한 Rating curve의 불확실성으로 인하여 본류와 지류의 유입량 추정이 어려웠던 섬진강 요천 합류부에 적용하였다. 대상구간은 본류(섬진강) 26km 및 지류(요천) 15km로 구성되어 있으며, 본류와 지류의 상류인 수위국 남원(신덕리) 관측소와 남원(동림교) 관측소에는 각각 기존의 Rating curve가 존재한다. 불확실성이 높은 Rating curve의 고수위 구간에 대한 매개변수를 조정하여 다수의 Rating curve를 생성하고, 이를 기반으로 관측수위를 다수의 상류 시계열 유량자료(경계조건)로 환산하였다. 다음으로 이 유량자료를 기반으로 앙상블 모의를 수행 후 대상구간의 중간지점에 위치한 수위국(고달(고달교) 관측소, 송동(요천대교) 관측소, 곡성(금곡교) 관측소)에서 수위재현성(NSE, RSR등 활용)을 평가하여 최적 샘플 추출을 추출하였다. 추출된 샘플로부터 상류 경계지점의 적정 Rating curve 선정과 각 지점에서의 시계열 수위 및 유량을 역으로 추정하였다. 이를 통해 실제 유량측정결과 없이도 간접적으로 신뢰도 높은 유량 자료를 확보할 수 있음을 확인할 수 있었으며, 향후 수자원의 효율적 관리 및 홍수관리를 위하여 효율적으로 활용이 가능할 것으로 생각된다.

• Journal of Korea Water Resources Association
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• v.55 no.7
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• pp.557-563
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• 2022

The rating curve is required to convert measured stage into a discharge and is developed using the measurement. In the development of the rating curve, the segmentation position is determined by considering the hydraulic characteristic and channel shape, and subjective judgment of the Hydrographer may intervene in this process. The segmentation position is so important that it determines the overall form of the rating curve, and the incorrect segmentation can cause errors in the rating curve, especially in extrapolation. In order to develop an accurate rating curve with a small number of measurements, the sections must be divided by considering hydraulic characteristic such as the cross-sectional shape. In this study, hydraulic examination methods such as stage-mean velocity, stage-area, stage-${\sqrt{Q}}$ investigated and supplemented to eliminate subjectivity in segmental positioning. Appropriateness for the segmentation position was verify in consideration of the physical meaning of the rating curve index (c).

• Journal of Korean Port Research
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• v.12 no.1
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• pp.131-143
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• 1998

This paper presents derivation of stage-discharge curve for Yangsan river. To derivate of stage-discharge lationship is one of the essential research areas in the water resource field. It provides reliable data a long term planning and hydrologic quantity on water resource development by quantitative analysis. The rating curve derivated through 15 discharge-observation on Yangsan river basin in 1997 has been estimated Q=1283.0262-1553.3158H+477.2702H2. According to the rating curve, the highest water level 2.6m, the limited water-level should be bound to the maximum of 2.6m. Before this research, stage-discharge curve of Yangsan river has not been developed, and only 15 discharge observation(hydrometry) has been carried out though this research. Therefore it seems necessary to collect observation data through a long term process to obtain a reliable rating curve equation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.612-615
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• 2006

In this study, we compared and analyzed the floor impact noise insulation performance produced by the rating methods. The rating methods are using reversed A-weighting curve, A-weighted sound pressure levels(dB(A)). The results of this study are(1)dB(A) by the specified frequency is 0.5dB(A) at light weight and 2.5dB(A) at heavy weight upper than all pass dB(A)(2)the rating using reversed A-weighting curve is 5dB lower than dB(A)(3)the number of rating using reversed A-weighting curve mainly depends on impact noise pressure level of 63Hz in heavy weight but dB(A) does not.

• Korean Journal of Agricultural Science
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• v.51 no.1
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• pp.79-86
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• 2024

As the frequency and intensity of heavy rains increase, the vulnerability of agriculture to disasters also increases. Consequently, there is a need to improve flood and inundation predictions. To enhance the accuracy of inundation predictions, it is essential to monitor water level and discharge data within agricultural areas. This study was conducted to monitor water levels and rainfall in the Cheongju Sindae area from 2022 to 2023, and the data was utilized as input and validation data for agricultural inundation modeling. Four irrigation drainage canals were installed to a square-shaped concrete structure where the water level gauge is. It was then confirmed that the water level rises with rainfall. The flow velocities were monitored during periods of heavy rainfall. The rating curve, which estimates water level and flow velocity based on observations, was estimated using the software K-HQ. The resulting curve was presented with the Coefficient of Determination (R²). K-HQ was also used to calculate the equation for the rating curve, taking outliers into account at each data point. Outliers were extracted and the rating curve was recalculated. As the coefficient of determination of three out of four stations exceeded 0.95, the estimated rating curve may be considered reliable for discharge estimation. This study provides critical data for enhancing agricultural inundation modeling accuracy and drainage improvement projects.

• Journal of environmental and Sanitary engineering
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• v.23 no.4
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• pp.83-93
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• 2008

The non-linear least squares model(NLSM) has long been the standard technique used by hydrologists for constructing rating curves. The reasons for its adaptation are vague, and its appropriateness as a method of describing discharge measurement uncertainty has not been well investigated. It is shown in this paper that the classical method of NLSM can model only a very limited class of variance heterogeneity. Furthermore, this lack of flexibility often leads to unaccounted heteroscedasticity, resulting in dubious values for the rating curve parameters and estimated discharge. By introducing a heteroscedastic maximum likelihood model(HMLM), the variance heterogeneity is treated more generally. The maximum likelihood model stabilises the variance better than the NLSM approach, and thus is a more robust and appropriate way to fit a rating curve to a set of discharge measurements.