• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.588-597
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• 2015

This study was carried out to identify the reasons of the landslide by land creeping in South Korea in order to provide basic information for establishing the management plan for prevention. Total 29 sites of landslide areas caused by land creeping were observed in South Korea. Among them, the soil-composition of most frequent landslide areas occurred by land creeping was colluvium landslide as 75.9% (22 sites), followed by clay soil landslide as 10.3% (3 sites), bedrock landslide as 6.9% (2 sites), and weathered rock landslide as 6.9% (2 sites). According to the types of parental rocks, the investigated landslide areas were divided into 3 types: 1) metamorphic rocks including schist, phylite, migmatitic gneiss, quartz schist, pophyroblastic gneiss, leucocratic granite, mica schst, banded gneiss and granitic gneiss, 2) sedimentary rocks including limestone, sandstone or shale and mudstone, 3) igneous rocks such as granite, andesite, rhyolite and masanite. As a result, it was noticed that the landslides occurred mostly at the metamorphic rocks areas (13 sites; 44.8%), followed by sedimentary rock areas (12 sites; 41.4%), and igneous rock areas (4 sites; 13.8%). Looking at the direct causes of the landslide, the anthropological activities (71%) such as cut slopes for quarrying, construction of country house, plant, and road, farming of mountain top, and reservoir construction were the biggest causes of the landslides, followed by the land creeping landslides (22%) caused by geological or naturally occurred (22%), and cliff erosions (7%) by caving of rivers and valleys.

• Geophysics and Geophysical Exploration
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• v.10 no.3
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• pp.163-172
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• 2007

A seafloor curvature measurement method was developed to extract redundant topographic features from the multi-beam bathymetry data, and then applied to the data of abyssal plain area in the Pacific. Any seafloor might be modeled to a quadratic surface determined in a linear least squares sense, and its curvature could be derived from the eigen values related with quadratic model parameters. The curvature's magnitude as well as polarity showed distinct relationship with geometric characteristics of the seafloor like as ridge and valley. From the investigation of curvature's variation with the number of data in the quadratic surface, the optimal size of data aperture could be applied to real bathymetry data. The application to real data also required the determination of the accompanying threshold values to cope with corresponding topographic features. The calculation method of previous studies were reported to be sensitive to the background noise. The improved curvature measurement method, incorporating the sum of eigen values has reduced unwanted artifacts and enhanced ability to extract lineament features along strike direction. The result of application shows that the curvature measurement method is effective tool for the estimation of a possible mining area in the seamount free abyssal hill area.

• Korean Journal of Plant Taxonomy
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• v.42 no.2
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• pp.116-125
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• 2012

The distribution, vegetation characteristics and an assessment of the conservation status of the Korea endemic species Coreanomecon hylomeconoides Nakai were investigated to collect biological basic data to formulate a conservation strategy. According to the distribution map of C. hylomeconoides based on the literature, specimen information, and local field surveys, natural populations of C. hylomeconoides are intensively distributed in the Southern regions of the peninsula, around Gyeongsangnam-do and Jeollanan-do. C. hylomeconoides was distributed in the middle and low slope adjacent to a valley. The altitude ranged from 227 m to 744 m, with inclinations of $5-10^{\circ}$. As a result of a vegetation survey within natural populations, a total of 238 taxa were identified from 29 quadrates in 8 natural populations. The importance value of C. hylomeconoides is 25.34% based on the coverage and frequency of the herbaceous layer with in the populations. The species diversity of the occurrence of the species in 8 natural populations was 1.52, while the averages of species evenness and the dominance values were calculated to be 0.83 and 0.17, respectively. As a result of assessing the conservation status through IUCN Red List criteria, C. hylomeconoides was evaluated as Near Threatened (NT). Conservation strategies are also discussed for the sustainable conservation of C. hylomeconoides.

• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.819-841
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• 2015

To investigate the distribution of vascular plants growing at Halmibong(1,026m) and Gusibong(1,014m) in Baekdutrail, we surveyed from March in 2013 to March in 2014. The flora of Haimibong and Gusibong in Baekdu trail were found to be; 528 taxa; 95 families, 287 genus, 454 species, 4 subspecies, 59 varieties, 11 forma. Rare plants were found to be; 15 taxa, 10 families, 14 genus, 13 species, 2 varieties. Among them EN degree was found to be 1 species(Rhododendron tschonoskii Maxim.), VU degree; 2 species(Scorzonera albicaulis Bunge, Lilium cernuum Kom.), LC degree; 12 species(Abies koreana Wilson, Coreanomecon hylomeconoides Nakai, Viola albida Palib. etc.) respectively. In all surveyed areas, a total of 15 taxa(Heloniopsis koreana Fuse, N.S.Lee & M.N. Tamura etc.) were found to be endemic to Korea. Distribution of floristic special plants in the surveyed areas were found to be divided into five classes (class I~V). The floristic special plants found in surveyed areas were 2 taxa of grade V, 6 taxa of grade IV, 12 taxa of grade III, respectively. The naturalized plants were investigated as 23 taxa; Rumex crispus L., Amorpha fruticosa L., Veronica arvensis L. etc..

• Korean Journal of Environment and Ecology
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• v.27 no.5
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• pp.614-624
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• 2013

The purpose of this study is to offer the raw data for establishing the plan of disaster prevention and the continuous conservation of soil ecosystem by grasping the potential soil loss and the danger of erosion using RUSLE method on whole districts in Gyeongju National Park, Korea. In the results of the average amount of soil erosion for the year, the average of all districts was 5.7 ton/ha in annual, and Namsan district was the highest in 7.6 ton/ha in annual and Seoak district was the lowest in 2.1 ton/ha in annual. The dangerous district due to the soil erosion was analyzed as under 1%, and Gumisan and Hwarange district was not serious. But Namsan district was higher than others, especially, there was intensive in all over Geumohbong. Therefore, to protect the all over Geumohbong, we will establish the valid of restoration and management. The types of land cover in Gyeongju National Park mostly showed forest, and as the average amount of soil erosion in forest was 3.7 ton/ha in annual, there was good condition. In the results of the amount of soil erosion due to landform, the deep canyon showed as 7.3 ton/ha in annual per unit area, secondly, the U-shaped valley was analyzed as 6.1 ton/ha in annual. The plain and high ridge were predicted that there occurred the small amount of soil erosion. In future, if we will analyze the amount of soil erosion in Korean National Parks, we will offer the help to establishing the plan of conservation and restoration on soil ecosystem in whole National Parks.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.4
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• pp.55-64
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• 2017

In order to assess the spatial and dynamic changes in bamboo forests, this study used the national-level spatial data between 1980 and 2010 to extract spatial information of bamboo forests through GIS technology. The results showed that the distribution types were mainly expansion, normal, mixed, damage, and separation. In case of mixed bamboo forest in the Sacheon region, the expansion characteristics were: area 2.5 ha, velocity 0.08 ha/yr, and distance 1.1 m/yr. The Phyllostachys pubescens forest in the Geojae region showed the following characteristics: area 1.9 ha, velocity 0.06 ha/yr, and distance 0.9 m/yr with where along from valley to ridge. This approach could provide a valuable tool for decision-making and implementations such as the bamboo forest management plan, environmental impact assessment for a preventing the bamboo expansion, and sustainable managing the bamboo resources.

• The Korean Journal of Ecology
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• v.3 no.1_2
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• pp.21-30
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• 1980

This paper contains the results obtained by ecological investigation of flora in Muie Island of Incheon Harbor in the western coast in Korea. 14 varieties, 147 species, 57 families and 142 genera of Tracheophyta were recorded by field investigations conducted over three times in May and July, 1976 and August, 1980. The flora of this island showed a plant community predominated by Pinus densiflora grown in miggle with Carpinus laxiflora, Quercus serrata and Rhododendron mucronulatum. Generally, the number of plant species was scarce, but it was an unexpected result that such remote mountainous plants as Lysimachia clethroides, Syneilesis palmate and Lilium disticum etc. were encountered in a wood surrounding Seohwang-dang, the shrine of a tutelary deity, on 126-Meter Hill at the northern end of the island. There also countered in Hoyong mountain valley were deciduous broad-leaved forests without pine tree which mainly consisted of Prunus leveilleana, Fraxinus rhynchophylla, Platycarya strofilada, Quercus serrata, Quercus acutissima and Acer mono. In addition, herbaceous plants, such as Syneilesis palmata, Codonopsis lanceolata and Lysima barystachy were grown as the undergrowth of these forests. Drosera rotundifolia, an unlooked-for plant, appeared in the middle of the eastern coast of the island. Camellia jpaonica was gro주 spontaneously in Deogjeog Island 26km southwest from the island, while no evergreen broa-leaved tree could be located except 2 species of Vitex rotundifolia and Euonyhmus japonica. It may be considered that such simple flora of this island compared with that of land is attributed to the fact that the formation of the former took place in the period far latter than that of the latter.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.66-66
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• 2010

야외지질학습은 교실에서 경험할 수 없는 물질과 현상을 관찰하고 직접 경험할 수 있는 기회를 제공받을 수 있어서 매우 중요하다(Orion 1989). 또한 체험활동으로서 교실에서 학습한 내용의 구체적인 예를 제공하여 교육과정을 촉진시키는데 중요한 요소로 인식되고 있다. 일반적으로 야외 활동은 교실 활동보다 학생들의 경험과 훨씬 더 밀접히 관련되어 있기 때문에 보다 의미가 있을 수 있다. 야외실습 중에서 얻은 경험은 학생들이 그가 관찰한 것에 대해 읽도록 동기화시키고, 교과서와 자연조건에서의 실제적 경험 사이의 차이를 연결해 주는 다리를 제공해 줄 수 있다(홍정수, 장남기, 1997). 야외학습을 위한 적절한 장소는 먼저 학습주제나 목표와 부합되는 곳이어야 하며, 지리적으로 가깝고 안전한 곳이어야 한다(김찬종, 2008). 그렇기 때문에 각 지역별로 학습주제와 부합된 지역을 선정하여 야외지질 학습자료를 개발하는 것은 무엇보다 중요하다. 따라서, 본 연구에서는 전북 남원 일대를 중심으로 한 야외지질 학습자료를 개발하는데 그 목적이 있다. 전북 남원지역은 한반도의 중요지괴에 해당하는 영남육괴 지리산지구에 해당하며 편마암 복합체를 기저로 이를 관입하는 수 차례의 화성활동과 지구조운동으로 복잡한 지질양상을 보인다. 또한 지리산 지역은 평안분지와 경상분지의 일부가 보존되어 있고 지질시대를 달리하는 각종 화성암류가 골고루 분포하여 각 지질시대별로 화성활동과 지구조 운동이 활발했음을 시사해준다. 본 연구에서는 남원 지역의 지질학적 특징을 관찰하기 용이한 지역을 대상으로 총 5곳을 선정하였다. 남원 시내에 소재한 춘향대교 아래 지역은 중생대 쥐라기에 관입한 저반상의 남원화강암과 페그마타이트가 다수 분포하는 곳이다. 이 지역에서는 무수히 많은 관입암체를 찾을 수 있는데 다수의 지진과 지각변동이 있었음을 알 수 있다. 두 번째 장소는 다양한 바위들을 관찰할 수 있는 구룡계곡 일대이다. 이 장소는 오랜기간 동안 물의 흐름에 의해 풍화와 침식을 받은 다양한 크기의 바위를 관찰하고 구별함으로써 풍화에 따른 원마도의 관계, 바위들의 배치 형태를 통해 고지형 및 고수류의 방향을 유추해 볼 수 있다. 남원에서 장수 방향에 위치한 만행산 주변에는 흑운모편마암에 우세한데, 이 지역에서는 흑운모편마암에 나타나는 변성구조로 볼 때 높은 열과 압력을 받은 광역변성작용을 받는 것으로 판단된다. 또한 관입암체 내에 다양한 맥들이 관입을 해와 이를 통해 관입암체들의 상대연령을 판단해보는 학습자료로 활용될 수 있다. 네 번째 장소는 남원시 인월면 인풍리 소재의 인월 피바위 지역이다. 이 지역에서는 압쇄상 화강암이 주로 관찰되는데 이는 기원암인 반상화강암이 동력변성작용을 받아 생성된 것이다. 다섯 번째 지역은 지리산 내의 뱀사골로 지리산 인근에 분포하는 대표적인 편마암인 반상변정질 편마암을 관찰할 수 있다. 변정이란 변성작용을 받는 동안 형성되는 것으로 변성작용을 받는 동안 생긴 것도 있으나 경우에 따라 생성당시 원래 모암속에 포함되어 있는 반정들도 있다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.4
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• pp.428-435
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• 2004

With the rapid and wide-spread use of cellular telephones much attention has been focussed on propagation in the urban area crowed with buildings and houses. It is often surrounded by hills, forests, and mountains. The importance of surface scattering intereference between transmitters and receivers on the rough surfaces has been interested and investigated. Therefore, a prediction method is necessary to estimate the influence of rough surfaces on microwave radio propagation. Moreover, most of the mobile communications are performed based on the digital communication system rather than the analog one. In this case, we must pay more careful attention to the signal delay caused by the phase delay due to the multi-path propagation. In this paper we have analyzed numerically scattering of electromagnetic waves from building walls by using FVTD(Finite Volume Time Domain) method. We consider three different types of rough surfaces such as periodic, random, and composite structures. We calculate the bistatic normalized radar cross section (NRCS) for horizontal and vertical polarization, and we take account of the conventional optical reflection which corresponds to the n-th Bragg reflection for periodic structures. In addition, we investigated what conditions are needed in order to be able to ignore the higher order Bragg reflection for the periodic structures.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.14-25
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• 2015

This study was carried out to classify forest communities and to aggregate forest cover types for the complex and diversified natural forest areas of Guryongsan, Sobaeksan, Baekhwasan, Sokrisan, and Baekhaksan in the middle part of Baekdudaegan. The vegetation data were collected by point-centered quarter sampling method. One thousand one hundred fourteen sample points were subjected to cluster analysis to classify 27 forest communities, which were aggregated into 7 representative forest cover types on the basis of community similarity from composition of canopy species. They were Quercus mongolica forest cover type, mixed mesophytic forest cover type, Q. variabilis forest cover type, Pinus densiflora forest cover type, the others deciduous forest cover type, Q. serrata forest cover type, and subalpine forest cover type. The Q. mongolica forest cover type was most widely distributed in the study areas. It was assumed that abundance of Q. mongolica might be negatively associated with species diversity. Mixed mesophytic forest cover type and the others deciduous forest cover type were commonly distributed in the areas of valley, on the other hand, Q. mongolica cover type and P. densiflora cover type tended to be distributed in the areas of ridge.