• 대한지구과학교육학회지
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• 제8권3호
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• pp.251-258
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• 2015

Ecosystems of the southwestern tidal flats in Korean peninsula have been seriously injured by human activities. The results are mainly due to the lack of public recognition and education on tidal flats. In particular, thoughtless visitors in tidal flats are giving rise up damages because of non-systematic experience programs to tidal flat ecosystems. Therefore, experience programs friendly to natural tidal flats are necessary as a plan to reserve tidal flats and to enhance the effects of environment education on the flats. Experience learning programs on tidal flats can divide into direct experience, indirect experience and local society works. Direct experience work must undergo tidal flats directly and consider on forming the flats with natural refinement functions. Indirect experience includes deeper knowledge on role, circumstance and ecosystems of the flats on the bases of direct experience on the flats. In addition, local society learning must have the feeling and understanding on socio-cultural characteristics of local society itself through above two works. Experience activity would be a kind of injuring one to tidal flats. However, appropriately planned experience and education works on tidal flats could be sustainable development to attract desirable human activity on coastal ecosystems.

• 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.

• 진공이야기
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• 제3권2호
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• pp.11-16
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• 2016

Tidal current energy is the most interesting renewable resources that have been less harnessed. Korea has globally outstanding tidal current energy resources and it is highly needed to develop a tidal current energy conversion system. It is reported that the total amount of available tidal current energy is approximately 6GW in Korea. A good tidal site candidate is required a large amount of fast moving water, bathymetry and seabed properties, no conflicts with other users and is close to a load and grid interconnection. In this review, we summarized the results of R&D projects regarding tidal current resources, utilization projects and demonstration test bed.

• International Journal of CAD/CAM
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• 제9권1호
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• pp.79-83
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• 2010

Tidal bore is a peculiar nature phenomenon which is caused by the lunar and solar gravitation. Based on the physical characters of tidal bores, in this paper we propose a novel method to model and render this phenomenon, especially the tidal waves in Qiantang estuary. According to Boltzmann equation for tidal waves, we solve it with the novel triangle mesh of Kinectic Flux Vector Splitting (KFVS) mode. Then a method combining a curve forecasting wave and particles model is proposed to render the dynamic scenes of overturning tidal waves. Finally, with some rendering technologies, various realistic tidal waves under diversified conditions is rendered in real time.

• Ocean and Polar Research
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• 제33권3호
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• pp.309-319
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• 2011

This is a preliminary study of the feasibility of obtaining reliable tidal current harmonic constants, using one month of current observations, to verify the accuracy of a tidal model. An inference method is commonly used to separate out the tidal harmonic constituents when the available data spans less than a synodic period. In contrast to tidal constituents, studies of the separation of tidal-current harmonics are rare, basically due to a dearth of the long-term observation data needed for such experiments. We conducted concurrent and monthly harmonic analyses for tidal current velocities and heights, using 2 years (2006 and 2007) of current and sea-level records obtained from the Tidal Current Signal Station located in the narrow waterway in front of Incheon Lock, Korea. Firstly, the l-year harmonic analyses showed that, with the exception of $M_2$ and $S_2$ semidiurnal constituents, the major constituents were different for the tidal currents and heights. $K_1$, for instance, was found to be the 4th major tidal constituent but not an important tidal current constituent. Secondly, we examined monthly variation in the amplitudes and phase-lags of the $S_2$ and $K_1$ current-velocity and tide constituents over a 23-month period. The resultant patterns of variation in the amplitudes and phase-lags of the $S_2$ tidal currents and tides were similar, exhibiting a sine curve form with a 6-month period. Similarly, variation in the $K_1$ tidal constant and tidal current-velocity phase lags showed a sine curve pattern with a 6-month period. However, that of the $K_1$ tidal current-velocity amplitude showed a somewhat irregular sine curve pattern. Lastly, we investigated and tested the inference methods available for separating the $K_2$ and $S_2$ current-velocity constituents via monthly harmonic analysis. We compared the effects of reduction in monthly variability in tidal harmonic constants of the $S_2$ current-velocity constituent using three different inference methods and that of Schureman (1976). Specifically, to separate out the two constituents ($S_2$ and $K_2$), we used three different inference parameter (i.e. amplitude ratio and phase-lag diggerence) values derived from the 1-year harmonic analyses of current-velocities and tidal heights at (near) the short-term observation station and from tidal potential (TP), together with Schureman's (1976) inference (SI). Results from these four different methods reveal that TP and SI are satisfactorily applicable where results of long-term harmonic analysis are not available. We also discussed how to further reduce the monthly variability in $S_2$ tidal current-velocity constants.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.516-519
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• 2005

The pilot tidal current power plant is to be constructed at the Uldolmok between Chindo and Haenam, during next year. and extensive coastal engineering research works have been carried out. In this paper we describes some observation results of the tide and tidal current. as well as modeling work in order to investigate the tide and tidal current regime change in relation to the tidal current power plant (TCPP) construction. The special modeling skill in order to consider the turbine operation in the TCPP is developed and applied to the estimation for the flow regime change by the simple layout of the tidal current power plant.

• 한국환경과학회지
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• 제4권2호
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• pp.245-251
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• 1995

Generally, It is Introduced to well-known other models without considering tidal current of the field. The paper presents field measurements and numerical model solving velocity field of Cheonsu Bay by two-dimensional tidal model. It was proved that this scheme is easy to handle complex topography. Computed results is represented characteristics of tidal current for Cheonsu Bay. The results of the study can be summarized as follows ; 1. Tide form number has 0.21 value. Tidal range estimated 630.3 cm on spring, 454.1 cm on mean and 277.9 cm on neap, respectively 2. Tidal current has semi-diurnal form. Distance of traveling observed 16.6 km on flood and 15.5 km on ebb. 3. Tidal velocity showed reversing current. It was found that tidal velocity above 100 cm/sec is about 20 %. 4. Computed results are in good agreement with the observed data. Applying the algorithm to Cheonsu Bay, velocity fields and dry bank phenomena are simulated well in spite of complex topography. 5. An advanced study on the effects of open boundary conditions should be continuously performed.

• 신재생에너지
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• 제1권2호
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• pp.73-78
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• 2005

The pilot tidal current power plant is to be constructed at the Uldolmok between Chindo and Haenam, during next year, and extensive coastal engineering research works have been carried out. In this paper we describes some observation results of the tide and tidal current, as well as modeling work in order to investigate the tide and tidal current regime change In relation to the tidal current power plant [TCPP] construction. The special modeling skill in order to consider the turbine operation in the TCPP is developed and applied to the estimation for the flow regime change by the simple layout of the tidal current power plant.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.141-144
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• 2006

The tidal pi lot plant is being built in the Uldolmok waterway using Its strong tidal current with maximum current of about 12knots, which is revealed from the first direct observation using ADCP, on February, 2002. a serious of field observations (for example, ADCP observation was tarried out both at February 2002 and September, 2003), along with numerical modeling, have been carried out over the last several years, in order to understand the tidal dynamics and to examine the related variables according to the tidal current power plant (TCPP) operation.

• 한국해양학회지
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• 제10권2호
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• pp.67-75
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• 1975

Tidal Flushing at the entrance channels of tidal bay or estuary in the central western coast of Korea; Gum River Estuary, Garorim Bay, Asan Bay, and Yeomha Estuary were studied with the recent data of current surveys measured by curret meter at three or five anchored stations along the section for one or two tidal periods at mean spring tide. Equilibrium relationship between tidal prism at mean spring tide and minimum flow area below the mean sea level of the channel in alluvial material was found as of O'Brien's (1931, 1969) study. Bed load transport in the tidal channel is balanced with the tidal flushing ability having a mean velocity of about 0.75m/sec or maximum velocity of about 1.25m/sec for a half tidal cycle over the section at mean spring tide which fairly agree with Brunn's study(1955, 1957). flushing actions for different hydraulic depth( mean depth) and bed material size in the channel were reviewed and found that it depend to a minor extent on the factors.