• International Journal of Contents
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• 제18권1호
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• pp.76-84
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• 2022

Tidal power generation plays a critical role in reducing greenhouse gas emissions. It uses a tidal force generated by gravitational force between the moon, the earth, and the sun. The change of seawater height generates the tide-generating force, and the magnitude of the change is the tide level. The tide level change has the same period as the tide-generating force twice a day, every 29.5 days, every year, and every 18.6 years. Sihwa Lake Tidal Power Station is Korea's first tidal power plant that began commercial power generation in August 2011 and has been accumulating a large volume of data on electricity production, power generation sales, sluice displacement, and tide levels. The purpose of this paper was to analyze the impact of the inefficiency factors affecting production and the tidal level change on tidal power generation and their characteristics using Sihwa Lake Tidal Power's operational performance data. Throughout this paper we show that tidal power generating operation is accurately predicting the trends of magnitude of tidal force to be periodical for each day. determining the drop to initiate the water turbine generator factoring the constraints on the operation of Sihwa Lake, and reflecting the water discharge through the floodgate and water turbine during the standby mode in the power generation plan to be in the optimal condition until the initiation of the next power generation can maximize power generation.

• 한국환경과학회지
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• 제23권4호
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• pp.661-672
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• 2014

Due to tidal force, it is very difficult to estimate the hydraulic parameters of high permeable aquifer near coastal area in Jeju Island. Therefore, to eliminate the impact of tidal force from groundwater level and estimate the hydraulic properties, tidal response technique has been mainly studied. In this study we have extracted 38 tidal constituents from groundwater level and harmonic constants including frequency, amplitude, and phase of each constituent using T_TIDE subroutine which is used to estimate oceanic tidal constituents, and then we have estimated hydraulic diffusivity associated with amplitude attenuation factor(that is the ratio of groundwater level amplitude to sea level amplitude for each tidal constituent) and phase lag(that is phase difference between groundwater level and sea level for each constituent). Also using harmonic constants for each constituent, we made the sinusoidal wave and then we constructed the synthesized wave which linearly combined sinusoidal wave. Finally, we could get residuals(net groundwater level) which was excluded most of tidal influences by eliminating synthesized wave from raw groundwater level. As a result of comparing statistics for synthesized level and net groundwater level, we found that the statistics for net groundwater level was more insignificant than those of synthesized wave. Moreover, in case of coastal aquifer which the impact of tidal force is even more than those of other environmental factors such as rainfall and groundwater yield, it is possible to predict groundwater level using synthesized wave and regression analysis of residuals.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.173-173
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• 2015

The flood water level in tidal river is determined by the joint effects of flood discharge and tidal water levels at downstream boundary. Due to the variable tidal boundary conditions, the evaluated design water levels associated with a certain flood event can be significantly different. To avoid determining of design water levels just by a certain tidal boundary condition and remove the influence of variability in boundary condition from the evaluation of design water levels, a probabilistic approach is considered in this study. This study focuses on the development of a method to evaluate the realistic design water levels in tidal river with taking into account the combined effects of river discharge and tidal level. The flood water levels are described by the joint probability of two driving forces, river discharge and tidal water levels. The developed method is applied to determine design water levels for the tidal reach of the Han River. An unsteady flow model is used to simulate the flow in the reach. To determine design water levels associated with a certain flood event, first, possible boundary conditions are obtained by sampling starting times of tidal level time series; then for each tidal boundary condition, corresponding peak water levels along the channel are computed; and finally, design water levels are determined by computing the expectations of the peak water levels. Two types of tides which are composed by different constituents are assumed (one is composed by $M_2$, and the other one is composed by $M_2$ and $M_2$) at downstream boundary, and two flood events with different maximum flood discharges are considered in this study. It is found that (a) the computed design water levels with two assumed tides have no significant difference for a certain flood event, though variability of peak water levels due to the tidal effect is considerably different; (b) tidal effect can reach to the Jamsil submerged weir and the effect is obvious in the downstream reach of the Singok submerged weir; (c) in the tidally affected reach, the variability of peak water levels due to the tidal effect is greater if the maximum flood discharge is smaller.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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• pp.375-377
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• 2006

This paper presents a method to calculate generation power for integrating Sihwa tidal power into power systems. The sea levels of 1 minute interval using cubic interpolation based on the forecasted levels of high and low water offered from Nori(National Oceanographic Research Institute) are calculated. If the sea level is greater than the lake level and the difference between sea level and lake level at high tide is over the default value, it begins to calculate the tidal power. It is seen that tidal power can supply power to demand side stably and economically from assessment of effect for integrating tidal power into power systems.

• 한국해양공학회지
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• 제16권2호
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• pp.6-9
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• 2002

The long-term monthly variations of tide with tidal harmonic analysis in Pusan Harbour are investigated. The present spring tidal range decreased 1.4 cm and the variation of phase lag increased than 1974. The high and low water level of yearly mean sea level is show during the February to March and August to September, respectively. It is important to note that the larger lunar elliptic N2 is large in comparison with lunisolar diurnal K1 and principal lunar diurnal O1. The ratios (Correction Factors) of monthly mean sea level and the main 4 tidal constituents are evaluated to correct the shortly (monthly) observed tide for the design of harbour facilities.

• 한국해안·해양공학회논문집
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• 제23권5호
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• pp.393-400
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• 2011

경기만과 같이 지형이 복잡하고 조차가 큰 해역에서는 활발한 물질순환이 나타난다. 이러한 물질순환에 영향을 주는 장주기 흐름은 다양한 외력에 의하여 형성되며 시공간적으로 독특한 특성이 나타난다. 본 연구에서는 경기만에 위치하는 인천항부터 잠실수중보 사이에서 동기간에 관측된 조위와 유속자료를 분석하여 장주기 조류성분의 주기적인 변화 특성과 발생 기작을 파악하였다. 염하수로와 한강하구에서는 배조나 복합조와 같은 비선형분조의 증가로 인하여 조석파의 변형이 발생하고 이에 따른 평균해면 상승이 나타난다. 경기만으로부터 한강으로 전파하는 조석파는 수로폭과 수심이 크게 감소하는 염하수로로 진입하면서 급격히 변형되어 저조위와 평균해면이 상승하며, 상류로 갈수록 조석변형이 커진다. 이러한 조석변형은 조차가 큰 대조기에 증가하고 조차가 작은 소조기에 감소하며 주기적인 변동을 나타내는데, 이는 장주기 조석성분인 $M_{sf}$ 분조로 해석될 수 있다. 조석변형의 공간적 차이에 의해 발생하는 해면 경사는 대조-소조의 주기와 동일한 주기를 보이며 대조기에 증가한다. 해면 경사의 장주기 변동에 반응하여 조류의 장주기 변화가 나타난다. 이러한 장주기 조류성분은 상류에서 크게 증가하여 한강하류인 전류리 인근에서는 주요 분조인 $S_2$ 분조보다 크게 나타난다.

• 조명전기설비학회논문지
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• 제21권1호
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• pp.157-163
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• 2007

본 연구에서는 시화조력발전소의 계통 연계에 따른 발전량을 예측하여 평가하는 방안을 제안하였다. 국립해양조사원에서 제공되는 시화방조제의 대한 조석에 따른 고조(high water)와 저조(low water)의 해측 예측 자료에 대하여 보간법(interpolation)을 이용하여 1분 단위의 시화호 해측의 수위를 예측하였다. 예측된 시화방조제의 해측과 내측의 수위를 이용하여 시화조력발전소의 시간대별 발전량을 계산하였다. 계통 운영회사에서는 이러한 발전량을 근거하여 계통 기동정지계획 등에 활용할 수 있다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1982년도 제24회 수공학 연구발표회 논문초록집
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• pp.3-24
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• 1982

The relations between tidal fluctuation and freshwater discharge are stuied dy use of observed data in the estuarine region of the Nagdong Rivre. Damping modulus which represents the resistance to propagation of tidal wave is estimated, and it is verified that when the fresh water discharge is lower than 300 m/sec., the elevation of mean-water-level at Gupo is the same as mean sea-water-level.

• 한국환경복원기술학회지
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• 제2권3호
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• pp.1-9
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• 1999

This paper described the results of the characteristics of the near-bottom flow and field analysis of the tidal flats sediment. It was the aim of this paper to grasp current flow of tidal flat's environment and influence factor for environmental change forecast of tidal flats. Field measurement of water velocity, water elevation, bed materials test, and temperature distribution of tidal flat were conducted. Thereafter, current flow, turbidity and temperature distribution of tidal flat sediment have been discussed. The field research results showed that the fluctuating velocity near the seabed before and after its appearance at low tide was strongly affected by the wind wave. The resuspension of the sea-bottom sediment took place with great intensity before and after the appearance of the seabed at low tide. Both the sea water level and the weather condition were a significant influential factors. Such as, temperature and turbidity just on the surface and the shallow layer of seabed sediments were varied largely with time and weather conditions, but that its deeper layers was almost constant. Temperature on the seabed sediments was strongly influenced by irradiance and water depth. The temperature variation of the tidal flat and the variation characteristics of the current flow and turbidity depend greatly on the inhabiting environment of the tidal flat benthic organism.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.664-669
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• 2002

Intertidal zone (tidal flat) is a place which is sometimes dry and sometimes wet depending on the tidal rhythm. Direct measurement of topography in the intertidal zone is very difficult to be achieved. The interface between wet and dry parts in the tidal flat, which can be identified from near infrared band of satellite image, is a 'depth contour' which corresponds to the sea level at the time of satellite pass. Aquisition of topography data in tidal flat is possible by combining various techniques such as (1) identification of the interface between wet and dry parts, (2) GCP correction of satellite image, and (3) realtime prediction of sea level elevation at the time of satellite pass. The algorithm was successfully applied in obtaining topography (bathymetry) data in the intertidal zone of Asan Bay in the west coast of Korea from 26 satellite images. The method is expected to be very efficient in making bathymetry data base in the western and southern parts of Korea where tidal flats are well developed in wide regions.