• Journal of Fisheries and Marine Sciences Education
• /
• v.22 no.2
• /
• pp.180-194
• /
• 2010

Coastal sand dunes are dynamic and fragile buffer zones of sand and vegetation where the following three characteristics can be found: large quantities of sand, persistent wind capable of moving sand, and suitable locations for sand to accumulate. The functional properties of coastal sand dunes include the roles in sand storage, underground freshwater storage, coastal defense, and ecological environment space, among others. Recently, however, the integrity of coastal dune systems has been threatened by development, including sand extraction for the construction industry, military usage, conversion to golf courses, the building of seawalls and breakwaters, and recreational facility development. In this paper, we examined the development mechanisms and structural/format types of coastal sand dunes, as well as their functions and value from the perspective of coastal engineering based on reviews of previous researches and a case study of a small coastal sand dune in the Nakdong river estuary. Existing data indicate that there are a total of 133 coastal sand dunes in South Korea, 43 distributed on the East Sea coast (32 in the Gangwon area, and 11 in Gyeongsangbuk-do), 60 on the West Sea coast (4 in Incheon and Gyeonggi-do, 42 in Ghungcheongnam-do, 9 in Jellabuk-do, and 5 in Jellanam-do), and 30 on the South Sea coast (16 in Jellanam-do, 2 in Gyeongsangnam-do, and 12 in Jeju).

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
• /
• 1995.10a
• /
• pp.108-109
• /
• 1995

Hypoxia has persisted during summer in the bottom water of the lower portion of the Rappahannock Estuary, a western shore tributary of Chesapeake Bay. A laterally integrated two-dimensional, real-time model, consisting of linked hydrodynamic and water quality models, was developed to study the contributing processes for hypoxia. The hydrodynamic model gives the information of physical transport processes, both advective and diffusive, to the water quality model, which simulates the spatial and temporal distributions of eight water quality state variables. (omitted)

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.40 no.1
• /
• pp.127-133
• /
• 2020

Most sewage treatment plants located offshore are discharged to the shore either directly or through rivers. Therefore, the water quality of the treated water discharged from the sewage treatment plant affects the water quality of the river water discharged to the river and the ocean. In this study, field surveys and numerical simulations were conducted to investigate the effect of treated water from the sewage treatment plant adjacent to the coastal environment. As a result of analyzing the water quality and sediment quality with the samples collected from the river and the estuary where the treated water was discharged to understand the impact on the coast, the treated water discharged from the sewage treatment plant was discharged to the river without exceeding the design criteria. However, the water quality discharged to the shore through estuaries was more contaminated than treated water. The cause of water quality deterioration of coastal effluent is due to the sedimentation of estuary temporarily by longshore sediment sransport which appeared around the estuary, the occurrence of estuary obstruction, and the increase of stagnant time in the estuary. As it was released and discharged, it was analyzed to affect the water quality, water quality and marine life around the estuary. Therefore, in the case of the east coast where the longshore sediment transport is strong, when planning the sewage treatment facility discharged to the ocean, it is necessary to closely examine the water quality change of the river water in the treated water such as the river mouth occlusion by the longshore sediment transport.

• Journal of Navigation and Port Research
• /
• v.28 no.10 s.96
• /
• pp.925-931
• /
• 2004

Due to the development of Yongsan river estuary weir and Yongam-Kumho sea dike, Mokop coastal area is changed. Especially, Discharged water through Yongsan river estuary weir and Yongam-Kumho sea dike, may muse the environmental influences such as the changes of currents pattern and sedimentation in the vicinity of semi-closed Mokpo harbor. This study deals with the collection and analysis of discharge through estuary weir and sea dike, based on that, we analyzed a characteristics of a sea area from simulation. As the results of this study, it was known that discharge mused the changes of a tidal currents pattern and calculated depth variations showed close relation with tidal circulation.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
• /
• 2008.09a
• /
• pp.260-263
• /
• 2008

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
• /
• 2009.10a
• /
• pp.156-159
• /
• 2009

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
• /
• 2008.09b
• /
• pp.260-263
• /
• 2008

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.13 no.1
• /
• pp.56-60
• /
• 2001

Tidal asymmetry which is generated at the mouth of an estuary tends to be more serious toward the upper stream due to the growth of shallow tides. Thus careful observations and applications for the shallow tides are needed if studies related to sediment or pollutant transport are carried on. An aim of the present study was to clarify the characteristics of generation and propagation of shallow tides by various numerical experiments including the effect of inter-tidal zone. The results of the present study will give a fundamental guide for the analysis of tidal envirorunental changes and for the design of a numerical model if coastal constructions are conducted.

• Journal of Advanced Marine Engineering and Technology
• /
• v.32 no.4
• /
• pp.630-636
• /
• 2008

Monitoring the location of the shoreline and foreshore changes through the time and core tasks are carried out by coastal engineers for a wide range of research. With the advent of digital imaging technology, the shore-based video monitoring system provides many advantages than field surveys. This study presents the development and construction(installation) of video monitoring system to assist the study of coastal and shoreline dynamics and evolution, especially sandbar variation at the Nakdong river estuary. For the purpose of this study, at high building near the Dadea-po beach (St. 2) and Jinudo(island) (St. 1) foreshore region, where coastline variation is highly active, 5 video cameras installed; the coastline movement has monitored since Aug. 2007 using the systems. From the image results of video camera, the 'Spit' type sandbar appears at the foreshore region of Doyodeung and Dadea-po beach and measured the deposition process of Jinudo(island) foreshore region. As a result, the monitoring system using video-based technique built in this study would be able to identify changes in the area and width of shoreline and beach of Nakdong river estuary.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.2 no.1
• /
• pp.1-10
• /
• 1990

Experimental studies oil the density currents were made in order to investigate their hydraulic conditions in the estuary. Interfacial forms in the flow direction became sharply with increasing densimetric Froude number in the estuary which arrested saline wedge exists. Interfacial thicknesses were almost constant in the open channel, while they abruptly increased out of channel and they also decreased as overall Richardson number increases. Densimetric Froude number of river mouth showed that it was not necessarily 1.0 and varies with the upper layer thickness. On the other hand, water level there tended to increase with increasing relative densities. It is observed in the Sumjin River Estuary that a strong density front has been formed between freshwater and ocean waters.