• Journal of Environmental Science International
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• v.29 no.7
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• pp.703-713
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• 2020

In this study, carbon dioxide concentration and air temperature at different elevations were observed and analyzed in the upper atmosphere of mud flat and reed beds at low tide in Suncheon Bay. The carbon dioxide concentration and air temperature sensors were mounted on the drone, and the carbon dioxide concentration and air temperature by altitude (5 m, 10 m, 20 m, 40 m) at five points in the tidal flat and reed beds were observed in the morning and afternoon. The carbon dioxide concentrations in the upper atmosphere of the tidal flat ranged from 453.0 to 460.2 ppm in the morning and 441.6 to 449.7 ppm in the afternoon. The carbon dioxide concentrations in the upper atmosphere of the reed beds ranged from 448.9 to 452.4 ppm in the morning and 446.0 to 454.4 ppm in the afternoon. The carbon dioxide concentrations in the upper atmosphere of the tidal flat was higher in the morning than in the afternoon, and the carbon dioxide concentration decreased as the altitude increased. The carbon dioxide concentration in the upper atmosphere of the reed beds was similar in the morning and afternoon at all altitudes, and the carbon dioxide concentration decreased as the altitude increased. The correlation coefficient between carbon dioxide concentration and air temperature observed in the tidal flat in the morning was -0.54 ~ -0.77, and the correlation coefficient between carbon dioxide concentration and air temperature observed in the afternoon was 0.56 ~ 0.80. The correlation coefficient between carbon dioxide concentration and temperature observed in the morning in the reed field was low, below 0.3, and the correlation coefficient between carbon dioxide concentration and air temperature observed in the afternoon was 0.35 ~ 0.77. In the upper atmosphere of the tidal flats and reed beds, the linear function was suitable for the change of carbon dioxide concentration as a air temperature, and the coefficient of determination of the estimated linear function was higher in the afternoon than in the morning. Through this study, it was confirmed that the carbon dioxide concentration in the upper atmosphere of the tidal flat and the reed beds was different, and the increase rate of carbon dioxide concentration in the upper atmosphere of the tidal flat and the reed beds was higher in the afternoon than in the morning.

• Korean Journal of Remote Sensing
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• v.36 no.2_2
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• pp.263-275
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• 2020

In this study, DEMs (Digital elevation model) based on LIDAR, TanDEM-X and UAV (Unmanned Aerial Vehicle) are used to analyze topographic change of Gomso tidal flat during a few years. DEM from LIDAR data was observed at 2011 by KHOA (Korean hydrographic and oceanographic agency) and DEM based on TanDEM-X data was generated at Lee and Ryu (2017). UAV data was observed at KM and KH area of Gomso tidal flat. KM area was surveyed at MAY and AUG 2019, and KH area was surveyed at APR 2018 and MAY 2019. During research period, 2011 to AUG 2019, elevation of KM area is decreased 0.24 m in average, and Chenier is retreat to landward about 130 m. In KH area, elevation is increased 0.16 m in average during research period, 2011 to MAY 2019. It is expected that multi-platform remotely sensed data can help to study accurate topographic change of tidal flat.

• Economic and Environmental Geology
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• v.44 no.1
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• pp.59-70
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• 2011

The surface sediment distribution in a tidal flat in 2001 was compared with that of 2008 using high spatial resolution remote sensing images and a GIS-based analysis. Maps of the surface sedimentary facies for each time frame were induced by an IKONOS data acquired in February, 2001 and a KOMPSAT-2 data acquired in April, 2008 using an object-based classification method. The area ratio of each surface sedimentary facies were estimated, and the results were compared each other for deducing the change in the sedimentary facies during the time interval. The result showed that the percentage of grains larger than very fine sand (0.0625 mm) has increased considerably since the early 2000s in the Hwangdo tidal flat. Mud flat facies has decreased 5.81 % in the late 2000s compared with the early 2000s. However, mixed flat and sand flat have increased 4.46% and 2.14%, respectively. A field campaign also supported the result. This study showed that the monitoring of changes in the surface sedimentary facies in the tidal flat is possible through a GIS-based analysis using high spatial resolution remote sensing images.

• Geophysics and Geophysical Exploration
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• v.11 no.3
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• pp.197-203
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• 2008

A shallow high-resolution seismic reflection survey was carried out at the Mineopo tidal flat on the western coast of Korea. The purpose of the survey was to investigate shallow sedimentary structure of the tidal flat associated with the recent sea level change. A total of 795 shots were generated at 1 m interval from a 5-kg hammer source and recorded on 48 channels of 100 Hz geophones along two mutually perpendicular profiles. The water-saturated ground condition resulted in suppressed ground rolls by significantly decreasing rigidity. In addition, seismic velocities over 1500 m/s provided easy segregation of reflected arrivals from lower velocity noise. As a consequence, seismic sections from the study area show significantly higher resolution and signal to noise ratio than conventional land seismic sections. The tidal flat consists of 5 sedimentary sequences above acoustic basement. The seismic sections reveal the continuous structure of the tidal flat formed in association with sea level rise during the Holocene.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.3
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• pp.42-52
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• 2010

The purpose of this study is to produce digital elevation model (DEM) in the Jebu tidal flat, one of the west coast of the Korean Peninsula, by means of photogrammetric techniques from aerial digital stereo-images. Produced DEM would be become the fundamental data for change detection of the sediment and erosion. To do so, epipolar line is established by relative orientation. Area-based matching is then carried out based on this line and matching size according to surface property of tidal flat after a classified image is produced from reflectance and texture of the surface. As the results, DEM generated by the proposed method showed subtle changes in height more precisely than DEM using the fixed matching size and DEM by the commercial S/W in the region, such as tidal flats having few level differences.

• Journal of the Korean earth science society
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• v.25 no.7
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• pp.615-628
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• 2004

In order to elucidate seasonal sedimentary characteristics and depositional environment after construction of seawall on macrotidal flat, a seasonal observations of surface sediments (total 450) and sedimentation rates on 4 transects have been investigated for 2 years. The eastern area of Iwon tidal flat, has been changed from semi-closed coast to open coast by construction of seawall, shows general seasonal changes similar to characteristics of open coast type, which represented both fining and bad sorted distribution due to deposition of fine sediments under low energy condition in the summer, and relatively coarser and better sorted distribution because of erosion of fine sediments in the winter. In considering angles of transects, distribution patterns of surface sediments, the northern and southern parts of eastern tidal flat are dominantly influenced by wave and tidal effects, respectively. As time goes by, the eastern tidal flat shows coarsening-trend of surface sediments caused by direct effect of tidal current, were and typhoon. Meanwhile the western area of seawall, which has been re-formed by construction seawall, is sheltered from northwesterly seasonal wind. The seasonal change pattern of western area of seawall is slightly different from that of eastern tidal flat. Mean grain size and sorting of surface sediments during spring is finer and worse than those during summer. This seasonal change pattern maybe influenced by topographic effects caused from the construction of seawall. In consideration of all result, the transport of fine sediments in the study area, which is supplied to limited sediments, shows clockwise circulation pattern that fine sediments are transported from the eastern tidal flat to the western area of seawall because of blocking of seawall in the winter and are transported reversed direction the summer. As a result, many changes have been observed in the study area after construction of seawall; however, this change is still in progress and is expected to need continuous monitoring.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.402-402
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• 2005

The purpose of this study is to analyze the land cover environment changes of tidal flat in the Hampyeong Bay. Especially, it centers on the changes in the sedimentary environment using remote sensing data. Multi-temporal Landsat data (Path-Row: 116-034) were used in this study. Remote sensing data can be effectively applied for quantitative analysis of geological environment changes in the Hampyeong-bay.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.975-987
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• 2021

Potential habitat mapping of Meretrix lyrata which is found in large parts of South East Asian tidal flat was carried out to find out causes of collective death. Frequency Ratio (FR) method, one of geospatialstatistical method, was employed with some benthic environmental factors; Digital elevation model (DEM) made from Landsat imagery, slope, tidal channel distance, tidal channel density, sedimentary facesfrom WorldView-02 image. Field survey was carried out to measure elevation of each station and to collect surface sediment and benthos samples. Potential habitat maps of the all clams and the juvenile clams were made and accuracy of each map showed a good performance, 76.82 % and 69.51 %. Both adult and juvenile clams prefer sand dominant tidal flat. But suitable elevation of adult clams is ranged from -0.2 to 0.2 m, and that of juvenile clams is ranged from 0 to 0.3 m. Tidal channel didn't affect the habitat of juvenile clams, but it affected the adult clams. In the furtherstudy, comparison with case of Korean tidal flat will be carried out to improve a performance of the potential habitat map. Change in the benthic echo-system caused by climate change will be predictable through potential habitat mapping of macro benthos.

• Journal of Environmental Impact Assessment
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• v.21 no.5
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• pp.789-799
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• 2012

The major causes of environmental and social conflicts were analyzed through the samples of the construction and the management for tidal power plant abroad and inland. Based on the results, the eco-friendly and socially acceptable policy instruments for decreasing the scope and intensity of the conflicts were explored. Regarding environment issues, it was found that the tidal power project resulted in decreasing in tidal range and area of intertidal zone and in damaging to tidal flat and wetland conservation area. Also there are the characteristic change of tidal current and biological effect, etc. The major environmental and social conflicts were resulted from the distrust of environmental results to environmental impact assessment and prior environmental review and the distrust of project feasibility study, and insufficient activities of public participation. In this study, introduction to joint fact-finding(JFF) was reviewed as the measure of minimizing environmental and social conflicts.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.3
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• pp.53-63
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• 2010

The global sea level rise has an effect on eco-environmental change by the inundation and erosion in the coastal area. Forecasting model on the change of morpho-ecological environments by the sea level change will give us information for coastal area management by predicting environmental changes of the up-coming future. This research aimed to foresee eco-environmental changes by the sea level rise in coastal area. Prediction model used SLAMM model developed to forecast coastal changes by IPCC scenario. The model predicted centennial environmental changes in the mouth of Han river and Nakdong river, Suncheon and Hampyeung bay as case areas. To sum up the research findings, in the estuary of the Han river, tidal flat was gradually disappeared from the year 2075, scrubmarsh and saltmarsh belts were developed. In the Nakdong River estuary, scrubmarsh was decreased from the year 2025, tidal flat was deposited from the year 2050, and also, the Gimhae plain was partially inundated, and wetlands were formed. In the Hampyeung bay, saltmarsh was deposited in the year 2025, tidal flat expanded until 2050 was partially submerged after that time. Tidal flat of Suncheon bay was disappeared by the inundation after 2025, and saltmarsh was developed in the embayment.