• Journal of the Korean Geographical Society
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• v.49 no.3
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• pp.321-338
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• 2014

This study aims to identify spatial distribution of estuarine wetlands in Korea, and to assess temporal variation of the wetlands in the last few decades. Widely known in environmental and coastal management, watershed-based regions which composed with Han-river(western and eastern parts), Keum-river, Yeoungsan-river, Seomjin-river, Nakdong-river, and Jeju, are analyzed to evaluate temporal change of estuarine wetlands in the 1980s, 1990s, and 2000s, through the land-cover map. Results show that estuarine wetlands dramatically decreased in Han-river(western part), Keum-river, Yeoungsan-river that estuarine circulation have been interrupted with man-made structures such as dyke and drainage. But, estuarine wetlands surrounded by forests and grasslands has been relatively less damaged. Habitat diversity providing healthy estuary ecosystem is lower in interrupted estuaries than circulated estuaries, which are composed of tidal-flat, open water, salt marsh, rocky coasts and sandy shoreline. This study indicates that spatial distribution and temporal variation of estuarine wetlands are different with estuary type and region, so estuary type with seven regions can be applied to provides a framework for estuary management strategies and to establish estuary restoration plans.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.2
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• pp.103-111
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• 2013

In this study, field measurements were conducted in the section about 7 km from sea dike to westward. The observations of along channel current were carried out, and water temperature and salinity were measured simultaneously at 10 stations during one tidal cycle, and sampling interval is 1 hour. The maximum ebb current is about 1.5 m/s at the surface layer but flood current is 0.4 m/s at the bottom layer during discharge period. Residual current during river discharge shows two layer structures which is typical characteristic of the estuary system. On the other hand, residual current during a period with no discharge has shown multi-layer structure different from general estuarine systems. The distribution of high salinity can be seen at the bottom layer as the effect of discharge does not reach down to the bottom layer during discharge. As a result, freshwater is not effected at the bottom layer during observation, and mixing of surface layer to bottom layer is reduced by stratification.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.3
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• pp.274-294
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• 2007

The most reasonable method of counting the number of the estuaries in Korea may be counting the number of streams flowing into the sea. The number counting of the streams should be carried out based on the river classes (National River, Regional 1st Class River and Regional 2nd Class River) given by the River Act. The National River scale estuaries are totaled to thirteen, i.e. Han River(including Imjin River), Anseongcheon, Sapgyocheon, Geum River, Mankyeong River, Dongjin River, Yeoungsan River, Tamjin River, Seomjin River, Gawhacheon, Nakdong River(including West Nakdong River), Taewha River, and Hyeongsan River estuaries. The Regional 1st Class River scale estuaries are counted as four, i.e. Yeoungdeok Osipcheon, Samcheok Osipcheon, Gangneung Namdaecheon, and Yangyang Namdaecheon. While, the Regional 2nd Class River estuaries are arranged as the Province and counted as total 444; Jeonnam, Gyeongnam, Chungnam, Jeju Province have the 108, 94, 52, and 35 estuaries, respectively. The counted estuary numbers, however, can be slightly increased/decreased on what references are applied, e.g. whether or not including the streams lost estuary functions by the sea-dike construction or integrated nearby streams, and so on.