• Economic and Environmental Geology
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• v.14 no.2
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• pp.77-91
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• 1981

An airborne magnetometer survey was carried out over an offshore area of about $200,000km^2$ from the southeastern, southern and western part of Korea. Detailed magnetic studies on the geological structure of the southern part of above area ($100,000km^2$) was accomplished. Residual aeromagnetic map was made in order to delineate magnetic provinces, magnetic lineaments and sedimentary basins by application of least square method using computer system. To determine the depth of the sedimentary basins pseudo-gravimetric method was applied. 1. The area studied is divided into four magnetic provinces for the purpose of interpretation on the basis of the magnetic maps. 2. Near shore area and its attached islands of southern part (fiirst and second magnetic province) can be regarded as being the extension from the land geology due to presentation of strong magnetic anomalies and shallow magnetic basements. 3. Magnetic lineament 1-1 is strong magnetic anomalous region which is presumably relevant to volcanic activities in Cretaceous. The depth of magnetic basement of the lineament was determined to 1,500 m. Negative magnetic anomalous zones B1-1 and B1-2 which represent Tertiary basins showed depth of magnetic basement 3 km and 4 km each. The latter can be interpreted as extension of the Taiwan basin which is consisted of Tertiary sediments. 4. Magnetic lineament 2-1 coincide with Rainan-Fukien massif running NE-SW direction. A lineament located in central part of magnetic lineament 2-1 is well connected with extension of Sobacksan anticlinal axis on land. Volcanic rocks in Gyongsang system concentrated along this lineament. 5. The characteristics of magnetic pattern in the southern Yellow sea basin of western part of Jeju island show weaker magnetic anomalies and deeper magnetic basements than first and second magnetic provinces indicating geological structure of this basin seems to be quite different from that of Jeju strait. 6. In southern part of Jeju island, smoother magnetic pattern develope southward. Maximum depth of magnetic basement in sedimentary basins BIV-1 and BIV-2 were determined down to 6,000 m increasing its thickness toward Taiwan up to 11,000 m in the shelf area off Taichung, Taiwan. Judging from the fact that hydrocarbon was founded in the Tertiary sediments of western coastal area of Taiwan, it can be expected that hydrocarbon will be existed in these sedimentary basins of southern part of Jeju island.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.759-770
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• 1997

The general flow patterns in the Cheju Strait have been investicated by analyzing the current observations measured in $1986\~1989$ by current meter mooring in 3 north-south sections in the Cheju Strait and at 4 observation points around Cheju Harbour, and measured in $1981\~1987$ by drogue tracking. 1. In the Cheju Strait, there are eastward or northeastward residual currents, which implies that sea waters flow into through the whole western section and flow out through the whole eastern section in the Cheju Strait. The velocity of residual currents are $5.2\~30\;cm/sec$ in 10 m layer and $1.3\~24cm/sec$ in mid-bottom layer. Generally, the flow is strong along the deepest through and the northern part, and weak in the shallow areas near Chuja Islands and Bogil Island. 2. In the western entrance of the Cheju Strait, the observed mean residual velocity is 6.93 cm/sec and the volume transport is 0.384 Sv. There are a big discrepancy between the observed residual currents and the geostrophic currents. 3. Near the frontal areas northwest to Chuja Islands, warm and saline offshore waters, flow northward about 5 miles into the southern coastal areas of the Korean Peninsula in flood, and flow back rather eastward or southeastward than southward in ebb. So, warm and saline waters flow along coastal areas, being mixed with coastal waters. As a result, the northwestern area of Chuja Islands plays a role of the entrance of influx of warm and saline offshore water to the southwestern coastal areas of the Korean Peninsula. It should be stressed that this flow pattern is not due to the residual flows, but to the temporal (tidal) flows.

• Geophysics and Geophysical Exploration
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• v.10 no.4
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• pp.361-368
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• 2007

In this paper, we suggested the relationship between resistivity of coastal groundwater and NaCl equivalent salinity for the quantitative interpretation the results of surface/borehole resistivity and electromagnetic data. 38 groundwater samples having electrical conductivity higher than about 1,000 ${\mu}S/cm$ were analyzed to derive the empirical relationship between groundwater resistivity and NaCl equivalent salinity. We used Schlumberger chart GEN-8 to convert ion concentration from hydrochemical analysis to the equivalent NaCl salinity, and the portable meter to measure the in situ electrical conductivity of groundwater samples. From the hydrochemical analysis, relationship between the groundwater resistivity $(R_w)$ and equivalent NaCl salinity (Eq_NaCl) is expressed as Eq_NaCl=$5935.3551{\times}R_w^{-1.0993}$, and relationship between the groundwater electrical conductivity (EC) and total dissolved solids (TDS) is expressed as TDS=0.721*EC. We believe these relationships are very useful to assess the seawater intrusion in western and southern coastal area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.568-577
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• 2002

The spreading Cocuoainim polykikoides bloom in the southern coastal waters of Korea was simulated using numerical model including the physical processes of water flow and the chemical processes of increasing cell of C. polykikoides by uptake of dissolved nutrients. The circulation of sea water was simulated by two dimensional tide model reflecting the main four tidal components of $M_2,\;S_2,\;K_1,\;O_1$, and permanent current was driven by inflow/outflow across open boundaries. According to the result of model which tidal and permanent current were reflected simultaneously, eastward flows entering the southern waters from the western waters of Korea are dominant but westward flows are weak relatively. These result suggest that it is difficult for initial C. polykikoides bloom generated in the coastal waters of Goheung to move to the western coast of Korea through Jeju Strait. For spreading model of C. poiyhikoides, the range of generating distribution and the generating time of C. polykikoides bloom in coastal area are similar to those of observation data in the field. Wind is the most important factor in moving and distribution of red tide. Permanent current flowing eastward is also considered to be important factor and tidal current was a little influenced.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.04a
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• pp.219-228
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• 2002

Because western sea on the shore development is threatening sea ecosystem by decrease of silt and large size land-reclamation work by industrialization causes surrounding weather change and sea change, generate much changes bottom of the sea topography and coastline. Also, is influencing to route for safe entry into port of ship, departure. Therefore, this research did 0m boundary line, anxiety 2m line which appear to coastline of land portion and the border of silt using sea base level of lowest low tone side that is base line that appear because of sea waves to basis data numerical value Tuesday, numerical value by divide drawing that is changed to 4 area and analyze change degree of new airport construction and new town development, seashore by western sea district along the coast development of tide embankment construction and so on and bottom of the sea recognize.

• The Journal of Industrial Distribution & Business
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• v.7 no.3
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• pp.27-36
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• 2016

Purpose - Considering the importance of housing needs to real estate market, domestic studies on real estate prices from the perspective of demand are basically based on macro-data, but relatively few are associated with micro-data of urban real estate demand. We try to find a reliable relation of elasticity of demand and commercial housing market. Research design, data, and methodology - In this paper, we have derived housing demand theoretic method and have utilized micro-data of residential family housing survey of downtown area in Kunming City in October, 2015 to estimate income elasticity and price elasticity of housing demand respectively and make a comparative analysis. Results - The results indicate that income elasticity and price elasticity of families with owner-occupied housing are both larger than those of families with rental housing. Income elasticity of housing demand of urban residential families in Kunming is far below the foreign average and eastern coastal cities level, however, the corresponding price elasticity is far higher. Conclusions - We suggest that housing affordability of urban families in western China are constrained by the level of economic development, and the current housing price level has exceeded the economic affordability and psychological expectation of ordinary residents. Furthermore, noticing the great rigidity of housing demand, the expansion space of housing market for improvement and for commodity is limited.

• Proceedings of the KSRS Conference
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• v.2
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• pp.535-538
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• 2006

The coastline of the Choa Phraya Rivermouth in the Upper Gulf of Thailand has been changed drastically. The western side especially at Ban Laem Sing was eroded for 400 meter in 26 years or with the rate of 15 meter per year on the average. The Metropolitan Electricity Authority has granted five years research project to us to study the efficiency of the electric pole fence as a mean to reduce the wave force and increase sedimentation rate inside for mangrove replantation. If the method works efficiently, it will be used to reclaim the coastal land loss in other areas in Thailand. The project was done since 2005 after the fence was constructed completely in October 2005. The oceanographic surveys were conducted before and after the construction in northeast monsoon season to study the impact of physical oceanographic forces on the coastline change. The sedimentation rates were measured each month. It is rather low about 2 cm/month. The subsiding rate from the load of deltaic sediment and groundwater withdraw using boring data is about 30 mm/year. The cumulative sinking rate is 55.8 cm from 1978 to 1995. We have tried to design the method of mangrove plantation in this area. The remote sensing data such as LANDSAT and aerial photos from 1987 to 2002 for 15 years were used to compute the rate of coastline change at each 50 m section along the western side of the rivermouth.

• The Korean Journal of Quaternary Research
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• v.9 no.1
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• pp.43-60
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• 1995

The Kanweoldo Deposit in the Cheonsoo Bay western coast of Korean Peninsula is considered to be influenced by severe freezing condition under cold humid environment of the last glacial age. The evidence of severe freezing in the some upper part of the fine-grained Kanweoldo Deposit is characteristically irregular wavy la-mellar structure with the interval of 2∼8mm. In particular lamina show very compacted fabrics composed of rounded or spheroidal discrete aggregates covered by silt caps. Such laminar structure and associated micro-fabrics might owe to soil freezing such as ice segregation in lens form cryophoresis pressure from growing ice and disturbance by frost-creep. Furthermore pedogenesis of cold-humid type such as gleyzation or peseudo-gleyzation also might af-fect the kanweoldo Deposit in the priod of severe cold-humid cli-mate of the Wrm. The Kanweoldo sediment and organic remnant(16,708 B.P. with error limit of 250 years) affected by severe cryogenic activities sug-gest that the paleoclimate of Late Wrm in Korea might be so cold and humid as to engender the cryogenic structure in subaerial silty and sandy silt deposits.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.3
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• pp.170-179
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• 2020

Tidal asymmetry would occur owing to shallow water tides at the Western Coast of macro tidal area. Especially, as ebb dominance of Mokpo coastal zone is known as the most prominent in Korea, it had been studied by domestic researchers. The cause of ebb dominance in Mokpo area is considered due to extensive inter-tidal zone in Muan Bay, and this has been studied based on amplification ratio, relative phase and skewness of tide/tidal flow curves in order to analyze qualitative tidal asymmetry. Furthermore, it was possible to figure out tidal characteristics with the difference of tidal amplitude and phase with Mokpo Harbor by observing the tide for 15 days in Muan Bay, which showed 40 minutes shorter ebbing time than at Mokpo Harbor. In addition, tidal flow prediction data in Mokpo North Harbor and Mokpo-Gu were analyzed. Meanwhile, the basis regarding qualitative interpretation of bed sediment and suspended sediment was provided by examining the qualitative changes in tidal asymmetry for spring-neap tidal cycle through the PCA/SWA indices. In addition, by examining long-term changes of ebb dominance in Mokpo Port, tidal characteristics of the past, present and future in this area, which is related to tidal asymmetry, is also provided.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.28 no.4
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• pp.158-177
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• 2023

An estuary is a transitional water area that links the land and sea through rivers and streams, transporting various components from the land to the sea, which plays an important role in determining primary productivity in the coastal environment, and this coastal ecosystem captures a huge amount of carbon into biomass, known as blue carbon, which mitigates climate change as a potential carbon reservoir. This study examined the variation of mean grain size and organic carbon content of the surface sediments for 6 years and analyzed their relationship in the western and southern estuarine areas (Han River Estuary, Geum River Estuary, Yeongsan River Estuary, Seomjin River Estuary, and Nakdong River Estuary) and the East Sea upwelling area. During the sampling period (2015 to 2020), seasonal variation of both properties was not observed, because their variations might be controlled by diverse oceanographic environments and hydrographic conditions within each survey area. However, despite the synoptic problem of all samples, the positive relationship was obtained between the averages of mean grain size and organic carbon content, which clearly distinguishes each survey area. The unique positive relationship in all estuarine areas implies that the same process by sediment clay particles is important in the organic carbon accumulation. However, additional important factor may be expected in the organic carbon accumulation in the East Sea upwelling area. Further necessary data (sedimentation rate, dry bulk density etc) should be required for the estimation of carbon stock to evaluate the major estuaries in Korea as potential carbon reservoirs in the coastal environment.