• The Korean Journal of Quaternary Research
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• v.7 no.1
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• pp.27-39
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• 1993

The shingle beach as a typical pocket beach located in Jeongdo-ri, Wando, Cheolanam-do, Korea has been investigated in terms of textural characteristics, mainly gravel shape and roundness. In the Jeongdo-ri gravel beach, changes of beach profile after storm weather and textural parameters of gravels were observed and measured from May 1992 to March 1993. Beach profile is divided into two different Fair-weather zone and Storm-weather zone influenced by dynamic condition of wave energy. The former is affected by wave and tide under fair-weather condition, the latter seems to be formed under storm-weather condition. Each zone comprises a series of beach faces and berms formed by continuous sedimentary processes of swash, overwash and backwash. Storm-weather zone is subdivided into three groups having a pair of beach face and berm respectively. Mean sizes of berm gravel(45.5 mm -123.6 mm) are coarser than gravels of beach face (36.8 mm - 78.3 mm) in fair-weather zone. On the other hand, in storm-weather zone, gravels of berms (33.1 mm -82.5 mm) are finer than those of beachfaces (46.2 mm - 105.2 mm). The proportion of disc shaped gravels of berm (50.0% - 58.5 %) is higher than that of beachface (45.9 % - 51.3 %) in each subzone except C-group of storm-weather zone. And the proportion of the equant shaped gravel increases about up to 10% seaward. Therefore, shore-normal distribution of gravels seems to be affected by shape and size sorting effects. Shore-parallel distribution pattern of gravel shape is more distinctive than size distribution patterns. That is, disc and blade shaped particles decrease up to 20% and 13% respectively, and equants increase up to 34% to the westward. Gravels plotted on Sneed and Folk's triangular diagram are more compacted and elongated with decreasing size. Therefore primary gravels are shaped by characteristics of country rock e.g. cleavage, joint etc., and secondary are affected by sorting and size-controlled process evolution by wave action.

• Journal of the Korean earth science society
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• v.40 no.1
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• pp.37-45
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• 2019

In spite of continued nourishments, Haeundae Beach in Busan has been suffering from erosion, this being caused by the increased wave energy due to global warming and intermittent typhoon reported by previous works. In the meantime, the typhoon Chaba hit Basan in October 2016. In order to investigate the effects of the typhoon in beach erosion and how fast the beach recovered after the typhoon, repeated beach profiling using a VRS-GPS system was carried out, and the grain size analyses for surface sediments sampled on the beach were conducted. Immediately after the typhoon invasion, Haeundae beach was eroded by 1.4 m in average height. The mean high tide lines were retreated back by 12 m, and beach slope became gentler from $3.8^{\circ}$ to $1.7^{\circ}$. The mean grain sizes of surface sediments became coarser from $1.6{\Phi}$ to $1.2{\Phi}$ after two months, and the sorting well sorted. After two months of typhoon landfall, the mean high tide lines have recovered by 85%, and the beach topography almost recovered. This suggests that the impact of typhoons on Haeundae beach erosion is negligible, and the relaxation time is shorter than that of other beaches.

• Journal of Environmental Impact Assessment
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• v.20 no.3
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• pp.257-267
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• 2011

This paper examines the spatial and temporal variability in the shoreline boundary caused by artificial structures in Songdo Beach of South Korea. Quickbird Images of 2003, 2005, 2007, and 2010 extracted from Google Earth were used to identify changing trends of shoreline boundary. The most significant changes were observed in area where groins were extensively established, inducing the sand beach much narrower than before in almost 75% of the area($15070.72m^2$ in 2003 to $3877.46m^2$ in 2010). The Google Earth made it possible to identify area-wide patterns of shoreline change subject to many different type of artificial structures, which cannot be acquired by traditional field sampling. Groin heights, lengths and profiles can be modified during maintenance operations if the Google Earth monitoring indicates that the initial layout is not operating properly as a physical barrier to control sediment transport. It is anticipated that this research could be used as a valuable reference to confirm the outputs from past field researches for coastal processes to respond to storms in more visual and quantitative manner.

• Journal of Soil and Groundwater Environment
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• v.8 no.1
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• pp.81-86
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• 2003

Understanding the penetration behavior of the spilled oil is very important to remove itself and to minimize its impact on intertidal biological communities by earlier treatment of the oil. The purpose of this study is to clarify the effects of wave and tidal actions on the penetration of spilled oil and to evaluate main factors of oil penetration using a sandy-beach model. Infiltration processes into the sediments showed significant difference between seawater and crude oil. Seawater was infiltrated by both wave action and tidal fluctuation into the sediments in sandy beach. However, spilled crude oil penetrated into the sediments only by falling tides and not by wave action, and the first tide is most important for the penetration of stranded oil. Over 70% of bulk fraction in penetrated crude oil was concentrated to the top 2 cm sediment-layer when spilled oil volume was 1 L/$\textrm{m}^2$. Moreover, the penetration of stranded oil into the sandy beach sediments was strongly correlated with the oil viscosity affected by temperature.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.3
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• pp.26-36
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• 2003

Collected and analyzed the coastal processes at the estuary of Nak-Dong river and its near coastal area from the history of field measurements. Introduced a numerical model to predict three dimensional topographical change which are evaluated from the nearshore wave and the wave induced current fields for the objective area, and later it were related to the development of beach and shoals. With the comparison between measured and calculated, we found that the changes on the coastline and sand spit and bar development are induced not only by artificial forces due to the construction of river dike, but also by the strong impact of wave induced current. In future days, it is expected that coastline change and sand bar development at the lee side of Jinwoo-Deung and at the front of Dadae beach.

• Journal of the Korean Geographical Society
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• v.36 no.4
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• pp.474-482
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• 2001

The purpose of this study is to investigate the formation and development processes of beach resort by fabric construction in a island environment. The results are as follows. (1) The research area(Tong-ri beach, Bokil-myon, Chollanam-do)has been transformed to belch by sedimentary environmental change since latter half of 1800's. (2) The mean slope of beach face is 0.96°, and the difference of attitude between beach and mud flat face is 75cm. (3) The mean particle size of beach surface sediment is 3.53$\Phi$. This value is very finer than that of any other beach in Korea peninsula. But its value is coarser than that of mud flat surface sediment. (4) The particle size distribution of core sediment is become changed to fine particle in 70cm depth. This value is corresponded to difference of altitude between beach face and mud flat face. (5) The analysis of aerial photographs after 1970 indicates that sedimentation process was not brisked since 1970's. Consequently, the research ares has been developed by sedimentary environmental change for sea-level rise effect and wave height energy rise effect.

• Journal of The Geomorphological Association of Korea
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• v.23 no.1
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• pp.117-128
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• 2016

High resolution aerial photographs and digital elevation models for Bangpo beach using UAV were generated in this study to analyze the thematic and geometric characteristics of coastal features. Based on 728 aerial images acquired on September 10, 2016 by the UAV, a image mosaic at 2.2 cm spatial resolution and a digital elevation model at 4.4 cm spatial resolution were developed. This study found out that Bangpo beach consisted of intertidal zone and supratidal zone. The intertidal zone can be subdivided into lower part and upper part with distinctive geomorphological characteristics. While the lower part included sand bars and ripple marks along the coastline, the cusps and sand dunes were the major coastal features of the upper part. Part of the intertidal zone was occupied by shore platform with average slope of 0.9 degree containing various sizes of gravels. The supratidal zone slanted toward ocean with berms on the surface with an interval of 15 m. These coastal features indicated the flow intensity towards to the land and tidal effect. It validated that the UAV application in coastal research was very effective analyzing to examine coastal processes.

• Journal of the Korean earth science society
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• v.24 no.6
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• pp.568-577
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• 2003

The purpose of this paper is to examine the geomorphic processes of beach and sanddune development in the Chungcheong-Namdo Province. The sands consist mainly of quartz and feldspar with lesser amounts of mica and other heavy minerals. With the exception of those from the granite, the sands have a very fine texture. Another characteristic of the sand grains is low degrees of roundness and grading indicating that source areas for the material were in the vicinity of the accumulating field. Over the years, the beaches have receded as a response to the decreasing amount of depositional materials. The driving force for the formation and transformation of coastal dunes in the study area is dominant winds from the center of the Siberian High. To some extent, the erosion of coastal dunes has been a global phenomenon. The degradation process occurred most actively when spring tides attacked beaches, berms, and foredunes. The relief and shape of present-day coastal dunes is determined initially by the Pleistocene strata underneath. From the fact that the strata contained traces of frozen structure, it can be inferred that sediment once experienced the process of soil formation.

• Korean Journal of Heritage: History & Science
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• v.46 no.1
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• pp.290-317
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• 2013

The objectives of this study are to investigate the natural heritage and scientific value of various geosites on Udo Island, and to evaluate the sites as natural monuments and as world natural heritage properties. Udo Island includes a variety of geoheritage sites. Various land forms formed during the formation of the Someori Oreum formed by phreatomagmatic eruptions. The essential elements for the formation of Udo Island are the tuff cone, overflowing lava and overlying redeposited tuff sediments. Various coastal land forms are also present. About 6,000 years B.C., when sea-level rose close to its present level due to deglaciation since the Last Glacial Maximum, carbonate sediments have been formed and deposited in shallow marine environment surrounding Udo Island. In particular, the very shallow broad shelf between Udo Island and Jeju Island, less than 20 m in water depth, has provided perfect conditions for the formation of rhodoids. Significant amounts of rhodoids are now forming in this area. Occasional transport of these rhodoids by typhoons has produced unique beach deposits which are entirely composed of rhodoids. Additional features are the Hagosudong Beach with its white carbonate sands, the Geommeole Beach with its black tuffaceous sands and Tolkani Beach with its basalt cobbles and boulders. Near Hagosudong Beach, wind-blown sands in the past produced carbonate sand dunes. On the northern part of the island, special carbonate sediments are present, due to their formation by composite processes such as beach-forming process and transportation by typhoons. The development of several sea caves is another feature of Udo Island, formed by waves and typhoon erosion within tuffaceous sedimentary rocks. In particular, one sea cave found at a depth of 10 m is very special because it indicates past sea-level fluctuations. Shell mounds in Udo Island may well represent the mixed heritage feature on this island. The most valuable geoheritage sites investigated around Udo Isalnd are rhodoid depostis on beaches and in shallow seas, and Someori Oreum composed of volcanoclastic deposits and basalt lava. Beach and shallow marine sediments, composed only of rhodoids, appear to be very rare in the world. Also, the natural heritage value of the Someori Oreum is outstanding, together with other phreatomagmatic tuff cones such as Suwolbong, Songaksan and Yongmeori. Consequently, the rhodoid deposits and the Someori Oreum are worth being nominated for UNESCO World Natural Heritage status. The designation of Someori Oreum as a Natural Monument should be a prerequisite for this procedure.

• Journal of the Korean Geographical Society
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• v.44 no.4
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• pp.481-496
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• 2009

Every coastal area exhibits its own unique landscape owing to the combination of the natural and cultural processes. Coastal barrier islands well show the cultural aspects of American coastal landscapes. Some 47% of barrier island area was occupied by urban and built-up area in New Jersey, while some 5% in Georgia. Tourism-related development is back to in the mid 19C. in N.J. due to the closeness to heavily populated areas such as New York and Philadelphia. Developments without proper understanding the nature of coastal processes caused New Jerseyization, the destruction of the beauty or naturalness. It was mainly due to the lack of growth-control policies and the foresight for the future coast in the processes of legislation. North Carolina's islands experienced an increase of 269% in urbanized acreage between 1956 and 1976. However, N.C. exercised her wisdom to recover the naturalness of the coastal environs: all engineering structures are banned on the beaches. Nine out of 13 barrier islands in Georgia exist in the wilderness condition owing to her unique history. The remaining islands still experienced the least development. After the Civil War most of Georgian islands were owned by rich families and maintained as wilderness. In the 1970s most of the uninhabited islands were sold or donated to research institutes or governmental agencies.