• Journal of Korea Water Resources Association
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• v.39 no.2 s.163
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• pp.179-186
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• 2006

We analyzed the harmonic and non-harmonic constant of Geum River estuary to know tidal change of the before and after construction at Geum River estuary dike. As a result of analysis, the harmonic and non-harmonic constant after estuary dike building increased. Also, depth change analyzed at each section by using each year chart data. As a result, scour was occurred in the channel between south and north side guide bank. And accretion was occurred at channel from Kunsan outer port to estuary dike. Tidal change was judged as the effect of construction and dredge, watergate closing at Geum River estuary dike. And water depth change is a cause by effection of Geum River estuary dike construction and, south-north side guide bank, Kunjang country industrial complex furtherance business, seamangeum 4th sea bankment construction.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.326-344
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• 2011

Although anthropogenic disturbance of 20 years duration affects benthic habitats, few studies have examined its effects on the macrobenthic communities of a bay. The aim of this study was to determine the influence of environmental variables on the macrobenthic communities after the construction of the Hwaong dike. Macrobenthos were collected at 22 sites using a Smith McIntyre grab (0.1 $m^2$) in August 2007 and February 2008. Total organic content was very low around the Hwaong dike. Sediment grain size increased from the Hwaong dike to the outer bay. In total, 317 species of macrobenthic fauna were collected and the mean density was 1,155 ind. $m^{-2}$, both of which were higher than the results of previous studies. The dominant species, $Hetermastus$ $filiformis$, known to be a potential pollution indicator, was more abundant near the Hwaong dike. Conversely, species sensitive to organic pollution, such as the polychaete $Ampharete$ $arctica$ and the ophiuroid $Amphioplus$ $squamata$, exhibited higher mean densities in areas distant from the dike. A cluster analysis indicated that the macrobenthic community was divided into two distinct groups: group I near the dike and group II in the outer bay, which were affected by sediment grain size and total organic content. This study suggests that variations in sediment grain size and organic content after dike construction are important factors controlling the macrobenthic community in Asan Bay.

• Ecology and Resilient Infrastructure
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• v.3 no.1
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• pp.8-13
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• 2016

This study investigated the effects of a spur dike on the development processes, the migration, and the wave length of alternate bars with laboratory experiments. The bar wave length was shown to be shorter as the spur dikes got longer. The forcing effects of a long spur dike on the behavior of alternate bars were stronger than those of a shorter one. However, the bar height was not affected by the variation of the length of a spur dike. The bar migration speed was in inverse proportion to the bar wave length.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.60-68
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• 2010

In this study, the seepage flow monitoring method by hydaulic head loss rate graph was developed for the purpose of monitoring the seepage flow from the see side or from the lake on sea dike in which seepage force was varied periodically. The hydraulic head loss rate was defined in this method. The value of the rate is in the range from 0 to 1. the value of 0 means perfectly free flow of seepage. the value of 1 means perfect waterproofing. The value of coefficient of determination in the hydraulic head loss rate graph closer to 1 means that the seepage flow way is stable. The value of coefficient of determination in the hydraulic head loss rate graph closer to 0 means that the hole may exist or the piping may be in the progress. The pore water pressure data measured in Saemangeum sea dike was analyzed with the developed method The result showed that the variation of seepage flow state was detected sensitively by this method and the interception effect of sea dike could be estimated quantitatively.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.1-8
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• 2013

This study was performed for the purpose of analyzing the effect of tide on the stress-strain behavior in the boundary surface of sea dike embankment. Tide is a dynamic condition, but there are not suitable numerical models to solve the dynamic embankment condition caused by tide. So the analysis was simplified to quasi dynamic as follow. First, seepage by tide was analyzed according to elapsed time, and the results of the analysis at every hour during one periodic cycle time of 12 hours were applied to the pore water pressure conditions of stress-strain analysis with hyperbolic model by Duncan and Chang. The place at which maximum shear strain took place in the analysis result moved up and down repeatedly along the boundary of the dredged sand fill section and the crashed stone filter section. The value of maximum shear strain was large at high water level of tide. This result means that contraction and relaxation occur in turn repeatedly at every specific position along the boundary, and the repeated action compact loose position with sand moved down from the upper position by gravity. The experiment with the small sea dike model showed the result consistent with the numerical analysis. The surface of sea side on the dike collapsed at high water level after a couple of repetition of the rising and falling of water.

• KCID journal
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• v.18 no.2
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• pp.43-53
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• 2011

In this study, the internal development of the Saemangeum basic concept of the changes being promoted as a lead construction and agricultural land works(54.2 km) has established a numerical model for the scenario. Inner dike to the construction site to reflect the following conditions to reproduce the numerical model by each areas during construction inner dike where scour expected to perform a numerical analysis for the hydraulic review by areas with possible future changes were to predict. Simulation results showed that numerical simulation results for scour expected frequency of 100 years in flood conditions is simulated with 0.02 m/s~l.27 m/s scour velocity for high-impact factor is considered to be stable. Each start point and end point work area of inner dike reviewed and flow rate of 100 years flood, the velocity distribution in the influx of a large flow rate of 0.02 m/s~1.68 m/s occur during construction inner dike are not being evaluated as a special issue does not occur will be considered according to the method and order of construction inner dike stability review suggests that the future need to be made.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.173-178
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• 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 cause 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 is known that discharge causes the changes of a tidal currents pattern and calculated depth variations showed close relation with tidal circulation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.4
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• pp.327-336
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• 2017

Fishing dredge in Jeollabuk-do began to become widespread in the 1960s and has continued to catch diverse kinds of shellfish in the productive fishing grounds around Dongjin River, Mangyeong River and Geum River estuaries. Since the 1970s, the construction of various large-scale industrial complex and the implementation of Saemangeum reclamation project have resulted in a decrease in main fishing areas and a sharp decline in shellfish production. As a result, dredge fishery has faced many difficulties. Dredge fishery in Jeollabuk-do is carried out with a total of 30 fishing permits as of 2016. Surf clams, hen clams, bladder moon snails, and common orient clams were mainly caught before the construction of Saemangeum dike while comb pen shells, purple whelks and ark shells are mainly caught afterwards. Inside the Saemangeum dike, most fish species have disappeared due to low water level and low salinity, and littleneck clams are caught using a jet pump type of fishing dredge. Outside the dike, the diversity of shellfish species has been reduced; comb pen shells are mainly caught. In this process, a lot of friction occurs due to the use of a reformatted dredge. Therefore, a lot of research needs to be conducted in the near future.

• Journal of the Korean Society of Safety
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• v.31 no.3
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• pp.53-59
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• 2016

Considering the chemical reaction between concrete which is the raw material of the dike bottoms and hazardous chemicals, some chemicals can have negative effects on the impermeability of concrete dike bottoms. The impermeable standards for the concrete bottom of dikes have been made in the recent study, but the previous study was based on the exposure test to crude oil which is not corrosive and not related to the chemical reaction. It can be concluded that the test of crude oil can't represent all kinds of hazardous chemicals, especially highly corrosive chemicals. Meanwhile, this study has conducted the exposure test to nitric acid that is strongly corrosive and very hazardous. The results have showed that nitric acid has been penetrated at the maximum penetration depth of 2.9 cm for 7 days and the impermeable standards are better than the germany standard. Through this study with severe chemical, the scientific basis on the installation standards of all dike bottoms which are generally used in the industry has been obtained.

• Korean Journal of Hazardous Materials
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• v.6 no.2
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• pp.7-12
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• 2018

Hydrochloric acid is a highly corrosive toxic substance and requires proper safety to minimize damage in case of leakage. Among the various risk-reduction facilities, the dike is a typical safety facility installed to protect the surrounding buildings and facilities by preventing the external spread of hazardous materials from the storage tank. In this study, the KORA program was used to assume leakage accident of hydrochloric acid storage tank. At this time, the extent of the damage effects of ERPG-2 were assessed for each of the three separation distance between the storage tank and the dike. The study found that the smaller the separation distance between the dike and the storage tank, the smaller the extent of damage caused by hydrochloric acid leakage, and the greater the impact of indoor conditions under the same conditions. Through this process, we are going to assist in selecting locations and installing facilities for new and existing businesses.