• Journal of Industrial Technology
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• v.20 no.A
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• pp.101-111
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• 2000

This research is results of experimental and numerical works on characteristic of strength increase and bearing capacity in dredged and reclaimed soil due to desiccation shrinkage. For a soil sampled from southern coastal area in Korea, basic soil property tests and standard consolidation test with falling head permeability tests were carried out to obtain consolidational characteristics of soil. Double cone penetration test, laboratory vane test and unconfined compression test were also performed to investigate the change of shear strength with degree of desiccation. Model tests were performed in 1G environment and 30G level artificially accelerated condition by using the centrifuge model test facilities to investigate the bearing capacity of desiccated ground. Test results were analyzed by using the theoretical and load-settlement characteristics method proposed by Meyehof & Hanna(1978). On the other hands, the numerical technique, using the finite strain consolidation theory considering the effect of desiccation was used to estimate the appropriate time of using heavy construction equipments in field with respect to strength increase due to desiccation.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.277-280
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• 2006

Many industrial fields were constructed on the reclaimed land which was used to be a tidal land. Because the industrial fields stand on weak basement, they are likely to be influenced by surface subsidence. Therefore, the surface subsidence monitoring is required for civil protection. In this study, a novel method to monitor land displacement, PSInSAR technique, was applied to monitor the land subsidence of Incheon Port, which happened a decade ago. Although the land was reclaimed more than 20 years ago, quite a bit of deformation was observed during six years. The maximum subsidence rate reached to 30 mm/year. JERS-1 data was exploited in this study.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.384-391
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• 2009

The coastline area, which was the important to decide the shape of the national land, has the characteristics of changing its shapes and features. We have some trouble to make the appropriate use-plan, because of the huge land to be reclaimed from the sea and developing large and small coast areas. Of them the coastal sand dune plays a definite primary role in the side of tourism and ecology. But there is not enough study for that. Busan Songdo coast is decided as an object of this study. We would analyze transfer path of the coastal sand dune through the time series analysis with RTK-GPS survey for many years. In case of Song do coast, the mean coastline length is approximately 620m, the area is approximately $31,846m^2$. Breakwaters are set up in right and left sides in Song do coast. it can make the sand dune be a minimum. So the coastal sand dune is steadily deposited with a certain beach nourishment of every year. As a result of 7 times survey, both sides of the coastal sand dune are eroded. It turns out it is going ahead over all as the center of the coastal sand dune is deposited.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.3
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• pp.233-240
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• 2013

Jakarta is the capital city of Indonesia which has problems of land subsidence with the rates of about 1 to 15 cm/year, up to 20-25 cm/year. The study has examined the land subsidence in Pantai Mutiara, Jakarta Bay which is a reclaimed area by using the Terrestrial LIDAR survey technique. The Terrestrial LIDAR survey results show that the survey site has mean elevation of 0.24 m with the highest elevation of 0.93 m and lowest - 0.35 m. Considering that AHHW (approximate highest high water) is 0.51 m, many areas of the survey site are lying below the AHHW. Pantai Mutiara area is showing various subsidence rates depending on sites although the site is relatively narrow and small (about 1 $km^2$). There is elevation differences of almost 1m within the site. In this study, key information including topography, dike height distribution, and future coastal flooding risk of the survey area was able to be provided by Terrestrial LIDAR survey conducted only once. Especially, as the 3D precision topography effectively conveys important messages relating to vulnerability of the site, policy makers and stakeholders can easily understand the situation of the site.

• Journal of Environmental Impact Assessment
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• v.8 no.3
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• pp.13-22
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• 1999

Tidal flow and water quality were simulated in this paper to assess environmental impact caused by pier construction projects in Onsan harbor system. The Surfacewater Modeling System (SMS) was applied to the Onsan harbor system, where coastal reclamation and dredging were planned to build the piers. A finite element mesh was constructed and refined to cover the complicated geometry of the Onsan harbor and the proposed reclamation area. The time variable change of tidal height at harbor inlet was given as an input condition to tidal simulation. The water quality simulation was based on the discharge rate of suspended solids at the reclamation area. The simulation results have shown reasonable agreements with real situations in both tidal flow and water quality. According to the proposed plan, tidal flow and water quality were predicted during and after the pier construction. The tidal simulation study showed that there would be no discernible change of tidal current in the harbor except for the dredged area. The water quality simulation, however, predicted that suspended solids would increase significantly near the reclaimed and dredged areas during construction.

• Journal of the Korean GEO-environmental Society
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• v.6 no.4
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• pp.47-58
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• 2005

Development of underground space is conducted for various useful facility and underground structures and deep excavation technology for reclaimed area has been researched and developed. The seepage flow and behavior of phreatic line in reclaimed area was predominated by transient flow caused by tidal action. Also the soil-water characteristic relation is most important factor for transient flow analysis, therefore the research about the soil-water characteristic is strongly required. In this paper, laboratory tests (pressure cell, desiccator, and tensiometer test) and theoretical analysis were performed to investigate the soil-water characteristic such as air-entry value, metric suction, and residual water content. And the feasibility of prediction method for soil-water characteristic are presented by transient seepage analysis and comparison between analysis results and in-situ measured seepage flux in LNG TK-00 storage tank. Based on the result of laboratory and theoretical analysis, Fredlund and Xing's method provide to work out well for reclaimed ground soils. Also, the transient analysis result is more reasonable and effective for design of deep excavation work in coastal and reclaimed ground.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.4
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• pp.97-102
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• 2007

Recently, coastal damage according to the natural disaster like storm-surge, overflowing of the sea has been massively increased. In case of earth fill at the seaside, there are a lot of weak areas of the natural disaster and it has also high possibility that a large disaster happens. Thus flood expectation map in the reclaimed land using 3D spatial information was produced in this study. The area around Myungji, Kangsugu, Busan which was made with the large scale earth fils at the seaside was designated as a study area. Observation of both costal datum and ground height using the tidal date and field surveying dates was conducted. Terrain model using the GIS program was produced and than 3D building model was produced using 3D MAX. It was shown that there are possibility more than 50% if over 4.5m storm-surge is happening, as a result of calculating the virtual flooded area on the produced cartographic map.

• Journal of the Korean association of regional geographers
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• v.11 no.2
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• pp.278-290
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• 2005

This study deals with the geomorphic, environmental and land use changes by comparative analysis using Landsat TM images of 1988 year and ETM ones of 2002 year, partly together with the new Quick Bird images having 60cm resolution for more detail analysis, focusing on the Oncheon gun(county) in Pyeongnam Province, west coast zone of North Korea. The main analysis methodology is neural network classification, which is more advanced techniques for the classification of land cover and land use, with higher accuracy rate and lower errors. The TM images of 1988 year show, mainly, the on-construction tide embank for the reclamation at Gwangryangman bay and salt farm on the reclaimed tidal flat. But, ETM images of 2002 year present stabilized reclaimed land, salt farm and rice field, recently transformed from salt farm. Especially, new tidal land has been naturally developed on the coastal shallow out of tide embank and salt farm. The results of the study may help to database coastal environmental changes and to support for reasonable and productive land use of North Korea, and to manage and plan unified national land in the near future.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.1
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• pp.1-6
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• 1984

Soils in Cheju Island, derived mostly from volcanic ashes, were collected for chemical analysis to determine the effect of land utilization pattern on soil chemical characteristics. The coastal area has long been used for intensive farming and some of the mid-mountain region were recently reclaimed for agricultural crop production. The cation exchange capacity and the organic matter in the soils increased in the order of coastal area < mid-mountain belt < upper mountain area, while pH, base saturation, available phosphorus and exchangeable bases decreased with the elevation. Generally, the organic matter, the cation exchange capacity and the exchangeable bases of the Cheju soils were found to be considerably higher than the Korean mainland soils. However, the base saturation and the available phosphorus were far below the mainland average. The ratio of monovalent basic cations to total exchangeable bases showed the highest in the soils of the mountain belts and the lowest in the coastal area soils. These data suggest that a higher soil pH in the coastal area as compared to the mountainous slopes has resulted not from the sea water but from continuous application of alkaline fertilizers and times.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.289-300
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• 2009

Flora distribution was surveyed in the newly reclaimed tidal flats in the west coastal area in Korea to understand changes in flora dynamics after reclamation. The surveyed reclaimed tidal flats were the newly reclaimed tidal flat in Hangdam, the mid Kyonggi Bay in 2002, and three reclaimed lands in Seukmun and Daeho, Chungnam, and Hangdam in Kyonggi Bay, of which reclamation years based on embankment were 7, 9 and 18 years, respectively. In the newly reclaimed tidal flat, the dominant flora was Suaeda japonica and other florae were rare, while various halophytes and glycophytes were distributed in the reclaimed lands. On the newly reclaimed tidal flat, four species of halophytic pioneer florae, Salicornia europaea, Suaeda glauca, Suaeda japonica, and Suaeda maritime occurred, and along with age facultative halophyte and glycophyte occurred sequently. On the reclaimed lands, the florae were more complex with various facultative halophyte and glycophyte, so these were predominated rather than pioneer halophyte, while one of pioneer halophyte that Suaeda japonica was not occurred. Increasing of various facultative halophyte and glycophyte, and decreasing of pioneer halophyte indicated that flora changed toward to increase of facultative halophyte and glycophyte by aged after reclamation. On the newly reclaimed tidal flat the ratio of flora species changed rapidly with the invasion of plant. This implied that the flora had begun to change in the early stage of reclamation. Facultative halophyte and glycophyte started to increase on the early stage of reclamation but relative density and frequency of pioneer halophyte was higher than facultative halophyte and glycophyte. According to the investigation up to 3 years after reclamation, pioneer halophyte predominated on it. Although flora changed, there were common representative halophytes among the reclaimed tidal flats: Salicornia europaea, Suaeda maritima, and Suaeda glauca as pioneer halophyte, Aster tripolium, Sonchus brachyotus, and Phragmites communis as facultative halophytes.