• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.3
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• pp.35-47
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• 2004

In order to study changes in vegetation pursuant to rooftop revegetation plantation methods, plantation methods for rooftop revegetation were divided into two types through an analysis of recent trends. Then, Planted plants and invasive plants on sites where the planting methods were introduced were monitored. Planting methods were divided into mono-layer meadow cover type and multi-layer planting cover type. They showed some differences in terms of the availability of wetland, the structure of vegetation layers, the planted species, and the material of mulching. According to the results of monitoring the two sample sites for different plantation methods, the number of invasive plants was higher in multi-layer planting cover type and the ratio of naturalized plants was higher by 30% in average in mono-layer meadow cover type. The main reason for such a result is that the natural soil used in the multi-layer planting cover type likely contained some seeds. Moreover, it's harder for invasive plant seeds to germinate in volcanic rocks than in natural soil. Also, it is attributable to wetlands available in multi-layer planting cover type and diverse living environments created by multi-layer planting. The reason of the ratio of naturalized plants being higher by at least 10% in mono-layer meadow cover type is the character of naturalized plants being stronger in unfavorable conditions than nature plants are. Accordingly, the germination rate in the volcanic rock mulching has likely contributed in raising the introduction and germination of naturalized plants. The results showed that multi-layer planting cover type using wetland creation and nature soil can increase the number of invasive plants and lower the ratio of naturalized plants. However, since seeds contained in the natural soil can affect the growth of planted plants, this needs to be clarified, It was judged that mono-layer meadow cover type may affect more greatly on the germination and growth of invasive plants than on those of planted plants, Its potential adoption in highly urbanized areas was examined. By complementing with the mutual benefits of each plantation method, it appeared possible to shift to a rooftop revegetation system suitable to the site.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1122-1129
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• 2010

Various soil tests were performed in the laboratory after soil samples were obtained from natural terrains distributed on the granitic rocks where are located in Mt. Bukhan, Mt. Surak and Mt. Gwanak around Seoul. Through the comparison of soil properties in each mountain, the difference of soil properties in a similar geological condition was investigated. According to the result of soil test, the soils were generally classified into calyey and silty sands with a well grade. Soil densities are ranged from $2.62kg/cm^3$ to $2.67kg/cm^3$, and water contents of soils are ranged from 3.77% to 31.12%. These values are not sorted locally. The wet unit weights of soils are ranged from $1.092kg/cm^3$ to $1.814kg/cm^3$. It has a big difference between the average values because that of Mt. Bukhan is $1.604kg/cm^3$ and those of Mt. Surak and Mt. Gwanak are $1.500kg/cm^3$ and $1.331kg/cm^3$, respectively. The internal friction angles are ranged from $31^{\circ}$ to $39^{\circ}$ and the cohesions are ranged from 1.57kPa to 8.63kPa. The shear strengths are too high and similar in all regions. The coefficients of permeability are ranged from $3.07{\times}10^{-3}cm/sec$ to $4.61{\times}10^{-2}cm/sec$. So, these soils are evaluated as a middle to high permeable ground. On average, the value of Mt. Bukhan is $1.47{\times}10^{-2}cm/sec$ and the values of Mt. Surak and Mt. Kwanak are $1.29{\times}10^{-2}cm/sec$ and $1.66{\times}10^{-2}cm/sec$, respectively.

• Journal of Soil and Groundwater Environment
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• v.18 no.1
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• pp.36-45
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• 2013

We analyzed natural radionuclides in 80 wells in volcanic rock areas and investigated environmental characteristics. Uranium and radon concentrations ranged from ND to $9.70{\mu}g/L$ (median value: 0.21) ${\mu}g/L$, 38~29,222 pCi/L (median value: 579), respectively. In case of gross-${\alpha}$, 26 samples exceeded MDA (minimum detectable activity, < 0.9 pCi/L) value and the activity values ranged from 1.05 to 8.06 pCi/L. The radionuclides concentrations did not exceed USEPA MCL (maximum contaminant level) value of Uranium ($30{\mu}g/L$) and gross-${\alpha}$ (15 pCi/L). But Rn concentrations in 4 samples exceeded USEPA AMCL (Alternative maximum contaminant level, 4,000 pci/L) and one of them showed a significantly higher value (29,222 pCi/L) than the others. The levels of uranium concentrations in volcanic rock aquifer regions were detected in order of andesite, miscellaneous volcanic rocks, rhyolite, basalt aquifer regions. Radon, however, was detected in order of miscellaneous volcanic rocks, rhyolite, andesite, basalt aquifer regions. The correlation coefficient between uranium and radon was r = 0.45, but we found that correlations of radionuclides with in-situ data or major ions were weak or no significant. The correlation coefficient between the depth of wells and uranium concentrations was a slightly higher than that of depth of wells and radons. Radionuclide concentrations in volcanic rock aquifers showed lower levels than those of other rock aquifers such as granite, metamorphic rock aquifers, etc. This result may imply difference of host rock's bearing-radioactive-mineral contents among rock types of aquifers.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.09a
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• pp.55-71
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• 2005

Jeju Island is mainly composed of basaltic lava flows and subordinate amounts of volcaniclastic sedimentary rocks. Jeju Province operates the monitoring wells for seawater intrusion problems around Jeju Island to evaluate of groundwater resources in coastal area. Various surveys and monitoring have been performed in boreholes, and also conventional geophysical well loggings conducted to identify basalt sequences and assess seawater intrusion problems. Various conventional geophysical well logs, including radioactive logs, electrical log, caliper log, and temperature and conductivity log and heat-pulse flowmeter log were obtained in 29 boreholes. The results of geophysical well loggings for saturated rocks are interesting and consistent. Natural gamma logs are useful in basalt sequences to sedimentary interbeds, unconsolidated U formation, and seoguipo formation with higher natural gamma log regardless of saturated or unsaturated basalts. Neutron logs are very effective to discriminate among individual lava flows, flow breaks, and sedimentary interbeds in saturated formation. In hyalocastite, porosity is high and resistivity is low, and we think that hyalocastite is a major pathway of fluid flow. In trachybasalt, porosity has a wide range and resistivity is high. In sedimentary interbeds, unconsolidated U formation and seoguipo formation, porosity is high and resistivity is low. The temperature logs in eastern area in Jeju are useful to interpret the hydrogeological unit and evaluate seawater intrusion in Suan area.

• Journal of Korean Society on Water Environment
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• v.33 no.4
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• pp.416-423
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• 2017

The subject samples include 150 and 170 samples collected from intake holes in the former and latter half of 2015, respectively. They were analyzed with ICP-MS. The average concentration of detected barium was $10.54{\mu}g/L$ ($0.23{\sim}168.22{\mu}g/L$) and $8.21{\mu}g/L$ ($0{\sim}255.65{\mu}g/L$) for the former and latter halves of 2015, respectively. The concentration distribution was the highest for the precambrian era at $19.07{\mu}g/L$ and the lowest Cenozoic era at $4.92{\mu}g/L$. The average value for sedimentary, metamorphic, and igneous rocks was $7.84{\mu}g/L$, $20.84{\mu}g/L$, and $9.47{\mu}g/L$, respectively, which indicates that it was the highest for metamorphic rocks. The study also analyzed correlations between barium and other minerals and found that magnesium recorded 0.44 and 0.71 for the former and latter half of 2015, respectively. As for barium concentration according to depth, it was relatively low in shallow groundwater (under 200 m) with its average concentration at $14.33{\mu}g/L$ and $14.71{\mu}g/L$ for the former and latter half of 2015, respectively. It was $8.53{\mu}g/L$ and $4.04{\mu}g/L$ in deep groundwater (over 200 m) for the two periods, respectively, The risk assessment results show that its average risk was HQ 0.00139 and HQ 0.00163 for the former and latter half of 2015, respectively, being considerably lower than "1", which suggests that barium poses few possibilities of consumption risk.

• Journal of the Mineralogical Society of Korea
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• v.18 no.1
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• pp.33-43
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• 2005

Three types of clinopyroxenes in alkali basaltic rocks from Jeju Island can be identified on the basis of geochemical and textural data. Type Ⅰ is Cr-rich diopside in spinel peridotites from the upper mantle. Type Ⅱ is augite in fine-grained pyroxenites which are possibly either magmatic vein or metamorphic segregations owing to anatexis of the upper mantle. The augite of Type Ⅱ contains high Ca and Mg and relatively low Ti. Type Ⅲ is thought to be either cumulates or cognate phenocrysts and can be subdivided into Ⅲa, Ⅲb, and Ⅲc based on their occurrence mode. Clinopyroxenes of Type Ⅰ have the highest Mg# and Si and the lowest Ti, whereas those of Type Ⅲhave lower Mg#와 Si and higher Ti. These geochemical characteristics indicate that (Ti+Al/sup Ⅵ/)/Si and Al/sup Ⅵ//Al/sup Ⅵ/ increase from Type Ⅰ to Type Ⅲ. It is possibly interpreted that Type Ⅰ is of the highest pressure origin and Type Ⅲ of the lowest. Fractionation of high-pressure clinopyroxenes would result in evolved undersaturated alkali-enriched liquids, probably producing the alkali-enriched host basaltic rocks in Jeju Island.

• Korean Journal of Environment and Ecology
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• v.23 no.5
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• pp.381-391
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• 2009

This is the study of the effects and changes on the ichthyofauna and fish community in Jeonju-cheon stream (located in Jeonju Cit, Jeollabuk-do, South Korea) after the implementation of the Natural Stream Restoration Project. The restoration of the stream was carried out between April 2000 and December 2002, and it covered the mid-section of the stream starting from the upstream of Hanbyeok Bridge down to Samcheon where branches of water join. It is 7.2 km long and passes through the downtown area. In this study, comparisons were made before and after the restoration. Before the restoration (1975 to 1999), the number of fish species collected from the Jeonju-cheon stream turned out to be 12 to 18 species, whereas after the restoration (2003 to 2008), it increased up to 34 species in total. Especially in the case of the middle and downstream sections running across the central regions of the city (Daga Bridge to Seosin Bridge), the number of fish species significantly increased from 5 species to 22 species. Such a dramatic increase of fish species appears to be directly related to the restoration of the stream which was designed to improve the quality of water by preventing polluted sewage water from running into the stream. Besides, the structure of stream bed which became more diversified into various components such as marshes and shallows, as well as rocks, Pebbles, sand and clay, also contributed to the increase of fish species.

• Korean Journal of Heritage: History & Science
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• v.47 no.1
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• pp.82-101
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• 2014

The purpose of this study was to survey and analyze the origin story and the legends associated with Yongyudam(龍遊潭, Dragon Creek), its scenic and spatial description in Climbing Writings(遊山記: Yusangi Notes), its geographical and geological features, its surrounding remains and letters chiseled on the rocks through the field study and the study on literatures associated with it so to identify its significance and value and then to ensure justification on preservation of Yongyudam scenic site. Conclusions of this study are as follow. As the traditional scenic place 'Geumdae-Jiri(金臺智異)' representing Hamyang-gun(咸陽郡) depicts Mount Cheonwangbong and 'Yongyudong Village(龍遊洞)', ancient maps and literatures have positioned Yongyudam as the center of Eomcheon-river Creek as well as the representing scenic site of Yongyudong Village. Core images in the spatial awareness of Yongyudam described in our ancestors' Climbing Writings Notes on Jirisan Mount are 'geographical and scenic peculiarity associated with swimming dragons', 'potholes in various shapes and sizes scattered on rocks', 'loud sound generated by swirling from shoals' and 'the scenic metaphor from the dragon legend', which have led scenic features of Yongyudam scenic site. In addition, significant scenic metaphors from legends such as 'Nine Dragons and Ascetic Majeog' and 'Kasaya Fish' as well as 'the Holy Place of Dragon God', the rain calling magic god have descended not only as the very nature of Yongyudam scenic site but also the catalyst deepening its mystic and place nature. On the other hand, Jangguso Place(杖?所, Place of Scholars) in the vicinity of Yongyudam was the place of resting and amusement for scholars from Yeongnam Province, to name a few, Kim Il-son, Cho Sik, Jung Yeo-chang and Kang Dae-su, where they experienced and recognized Jirisan Mount as the scenic living place. Letters Carved on the rocks at Jangguso Place are memorial tributes and monumental signs. Around Yongyudam, there are 3 stairs, letters chiseled on the rocks and the water rock artificially built to collect clean water, which are traditional scenic remains detectable of territoriality as the ritual place. In addition, The letters on the rock at Yongyudong-mun(龍遊洞門) discovered for the first time by this study are the sign promoting Yongyudam as the place of splendid landscape. The laconism, 'It is the Greatest Water in Jirisan Mount(方丈第一山水)' on a rock expresses the pride of Yongyudam as the representing scenic place of Mount Jirisan. Other than those, standing rocks such as Simjindae Rock, Yeong-gwidae Rock and Ganghwadae Rock show the sign that they are used as amusement and gathering places for ancestor scholars, which add significance to Yongyudam. By this study, it was possible to verify that Yongyudam in Mount Jirisan is not simply 'the scenic place in the tangible reality' but also has seamlessly inherited as the traditional scenic attraction spiritualized by overlapped historical and cultural values. Yongyudam, as the combined heritage by itself, shows that it is the product of the place nature as well as unique ensemble of cultural scenic attraction inherited through long history based on natural scenery. It is certain that not only the place value but also geographical, geological, historical and cultural values of Yongyudam are the essence of traditional scenic attraction, which should not be disparaged or damaged by whatever political or economic interests and logics.

• Journal of the Mineralogical Society of Korea
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• v.28 no.3
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• pp.279-292
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• 2015

New occurrences of large-scaled Zn-Pb deposits are recently found in the Danjang-myeon, Milyang. They are skarn-type deposits which replaced the intercalated limestone beds in the Jeonggaksan Formation. This study aims at characterizing occurrences, mineralogy, and chemistry of Zn-Pb ores and skarn minerals. Skarn orebodies are mainly found in 3 areas, named Gukjeon-ri, Gorye-ri, and Gucheon-ri orebodies, where sphalerite found as main ore mineral in 200-300 m in height and amount of galena increases as altitude does. Ores are dark grey to dark green in color and closely related with clinopyroxene zone. They occur with hedenbergite, grossular, actinolite, epidote, and small amounts of axinite, calcite, and quartz. Main ore mineral is sphalerite which includes tiny spotted grains of galena and chalcopyrite and becomes rich in grade in association with clinopyroxene and epidote. FeS contents in sphalerite show relatively wide range between 1.53 and 23.07 mole%, whose contents intend to increase towards biotite granite known as ore-related igneous rocks. CdS contents are in the range of 0.22-0.93 mole%, showing decrease tendency from southwest (Gukjeon-ri) to northeast (Gucheon-ri). Zn-Pb deposits developed in Danjang-myeon reveal decrease in temperature with increase of altitude, leading to gradual changes in compositions of ore and skarn minerals.

• The Journal of Engineering Geology
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• v.24 no.4
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• pp.535-550
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• 2014

The origins and varieties of natural radioactive materials, including uranium and radon-222, were examined in a drilled borehole extending to a depth of 120 m below the surface in the Goesan area. In addition to core samples, eight groundwater samples were collected at different depths, using a double packer system and bailer, and their geochemical characteristics were determined. Most of the rock samples from the drilled core consisted of granite porphyry, with sedimentary rocks (slate, carbonate, or lime-silicates) and pegmatite occurring in certain sections. The pH of samples varied from 7.8 to 8.4, and the groundwater was of a Na-$HCO_3$type. Uranium and thorium concentrations in the core were < 0.2-14.8 ppm and 0.56-45.0 ppm, respectively. Observations by microscope and an electron probe microanalyzer (EPMA) showed that the mineral containing the natural radioactive materials was monazite contained in biotite crystals. The uranium, which substituted for major elements in the monazite, appeared to have dissolved and been released into the groundwater in a shear zone. Concentrations of Radon-222 in the borehole showed no close relationship with levels of uranium. The isotopes of noble gases, such as helium and neon, would be useful for analyzing the origins and characteristics of the natural radioactive materials.