• Title/Summary/Keyword: Geomorphological characteristics

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Geomorphology and Geology of Gatbawi, Mokpo, Korea (목포 갓바위의 지형 및 지질 특성과 활용)

  • Kim, Hai-Gyoung;Moon, Byoung-Chan;Koh, Yeong-Koo;Youn, Seok-Tai;Oh, Kang-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.1
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    • pp.99-108
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    • 2012
  • To consider geomorphological and geological characteristics to Gatbawi(the 500th natural monument), it was investigated with the aspect of scale, form, mineralogy, chemistry and weathered state. Showing typically erosional features, micro-terrains as sea cliffs, sea notches, marine plateaus and tafoni developed well on coastal areas near the monument. Sea cliffs are vertical and form sea notches in their bases. Coastal terraces are 3.5m in width and 20m in trace. Tafoni are honey combed. The monument is mainly composed of quartz, plagioclase, microcline, biotite, sericite in mineral and corresponded to crystalline tuff dominated in quartz and plagioclase. It has 23.60~28.27 wt.% of $Al_2O_3$, 3.27~5.80 wt.% of $Na_2O$, and 0.11~0.20 wt.% of Cl in chemical contents, leveling higher than those of earth crust standards. It is considerably weathered on the basis of CAI(77.42~83.93%). The monument is very useful for natural perspective tourism and education. Therefore, it is necessary that several ideas as guide plates, observing telescope, explaining guider, education programs connected with related services, touring goods, picture for books on utilization on the monument must establish.

Present Status and Future Vision of EIA for Railroad Construction Projects (철도건설사업 환경영향평가의 현황과 과제)

  • Lee Hyun-Woo;Lee Young-Joon;Park Young Min;Yoon Mikyung
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.296-302
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    • 2004
  • After the Rio declaration on environment and development in 1992, developed countries are undertaking 'environmentally sustainable transportation (EST)' projects. To meet the needs for EST, current transportation policies in Korea are rapidly reforming and one of its concerns is modernizing and upgrading railway freight system. Planning new railroad construction projects is increasing and subsequent environmental impact assessment (EIA) demands improvements, especially in both the EIA and decision making systems. In this paper, we discuss the present status of EIA for railroad construction projects, especially, by analyzing the EIA documents accumulated for last six years. The EIA for railroad construction projects .accounts for only $4.9\%$ of total project EIAs during 1998-2003. However, the portion is gradually increasing. Major environmental concerns for EIA in railroad construction projects were geomorphological and ecological changes, protection of rare organisms, air pollution, water quality, wast management, noise, etc. We also compared the characteristics of environmental impacts of railroad construction with those of vehicle road construction. The result shows that railroad construction usually requires 3${\~}$4 times longer tunnels and bridges for a given length than vehicle road construction. In addition, the amounts of geomorphological and ecological changes (road-cutting, embankment, devegetation, etc.) in railroad construction were generally less than $40\%$ of those in vehicle road construction. In order to develop environmentally friendly railway systems, monitoring studies for environmental impacts of railroads such as habitat fragmentation and road kills, dispersal of alien plants, tunnelling effects on groundwater and vegetation, and noise impacts are highly required.

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Environmental Impact Assessment and Environmental Management of Railways (I) (철도사업 환경영향평가와 환경관리(I))

  • Lee, Hyun-Woo;Lee, Young-Joon;Park, Young Min;Lee, Jeongho;Yoon, Mikyung
    • Journal of Environmental Impact Assessment
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    • v.13 no.6
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    • pp.295-305
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    • 2004
  • After the Rio declaration on environment and development in 1992, developed countries are undertaking "environmentally sustainable transportation (EST)" projects. To meet the needs for EST, current transportation policies in Korea are rapidly reforming and one of its concerns is modernizing and upgrading railway freight system. Planning new railroad construction projects is increasing and subsequent environmental impact assessment (EIA) demands improvements, especially in both the EIA and decision making systems. In this paper, we discuss the present status of EIA for railroad construction projects, especially, by analyzing the EIA documents for the last six years. The EIA for railroad construction projects accounts for only 4.9% of total 918 project EIAs during 1998-2003, and the portion is gradually increasing. Major environmental concerns for EIA in railroad construction projects were geomorphological and ecological changes, protection of rare organisms, air pollution, water pollution, waste management, and noise, etc. We compared characteristics of environmental impacts of railroad construction with those of vehicle road construction, based on environmental and construction-planning indicators appeared in Environmental Impact Statements. Railroad construction usually requires longer tunnels and bridges for a given length than those for vehicle road construction. In addition, the amounts of geomorphological and ecological changes (road-cutting, embankment, devegetation, etc.) in railroad construction were generally less than 50% of those in vehicle road construction. To develop environmentally friendly railway systems, monitoring studies for environmental impacts of railroads such as habitat fragmentation and road kills, dispersal of alien plants, tunnelling effects on groundwater and vegetation, and noise impacts are highly recommended.

Relationship Analysis between Topographic Factors and Land Surface Temperature from Landsat 7 ETM+ Imagery (Landsat 7 ETM+ 영상에서 얻은 지표온도와 지형인자의 상관성 분석)

  • Lee, Jin-Duk;Bhang, Kon Joon;Han, Seung Hee
    • The Journal of the Korea Contents Association
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    • v.12 no.11
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    • pp.482-491
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    • 2012
  • Because the satellite imagery can detect the radiative heat from the surface using the thermal IR (TIR) channel, there have been many efforts to verify the relationship between the land surface temperature (LST) and urban heat island. However, the relationship between geomorphological characteristics like surface aspects and LST is relatively less studied. Therefore, the geomorphological elements, for example, surface aspects and surface slopes, are considered to evaluate their effects on the change of the surface temperature distribution using the Landsat 7 ETM+ TIR channel and the possibility of the image to detect anthropogenic heat from the surface. We found that the surface aspect is ignorable but the surface slope with the sun elevation influences on the surface temperature distribution. Also, the radiative heat from the surface to the atmosphere could not be accurately recorded by the satellite image due to the surface slope but the slope correction process used in this study could correct the surface temperature under slope condition and the slope correction, in fact, was not influenced on the average temperature of the surface. The possibility of the anthropogenic heat detection from the surface from the satellite imagery was verified as well.

Distribution of Vegetation and Geomorphology Characteristics of the Water Spider(Argyroneta aquatica) Habitat in the Jeongok Lava Plateau, Central Korea (전곡 용암대지 물거미 서식지의 지형특성과 식생 분포)

  • Lee, Min Boo;Lee, Sang Young
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.4
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    • pp.57-73
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    • 2017
  • The formation of the lava dam of the paleo lake blocked the entrance to the Chatancheon River on the Jeongok lava plateau and it suddenly transformed the terrestrial ecosystem into the aquatic one by the overflow. The spiders in the lava dam adapted in the wetland and evolved into water spiders that could survive by forming bubble houses. Since then, the lava dam was connected to the present Hantangang River due to the dissection and the lake became a terrestrial environment, a small area of marsh composed of primarily clay soil layer. Change in water level of the habitat and thus the extension of the terrestrial area made the species a endangered now. This study carried out frequency of occurrence, degree of wetness and plant habitats of the vascular plant in the water spider habitat. As a result of this study, total 180taxa are of 55 (30.6%) wetland plant groups and of 113 (62.8%) upland plant groups except facultative plant groups. Among the wetland plant groups, the Isachne globosa community occupied the largest area, where the water spiders were most observed. The result of this study, the classification and the types of vascular plant species, would provide useful information for the sustaining healthy wetland ecosystem and the restoration of the habitat for the water spiders.

Weathering Characteristics of Granitic Regolith in Southern part of the Korean peninsula (한반도 남부의 화강암 구릉대 지표피복물의 풍화 특색)

  • KIM, Youngrae;KEE, Keundo;YANG, Jaehyuk
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.4
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    • pp.123-137
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    • 2012
  • Reddish superficial materials in southern area of Korean Peninsula have been defined as lateritic red soil in Korea. In A-CN-K ternary plots, CaO and $Na_2O$ show similar linear distribution along a A-K line to kaolinite profile and laterite in southern Spain and Cameroon, respectively, and it means strong alteration. But $K_2O$ is weak alteration, plotting between muscovite and illite zone. Granitic reddish weathering mantles in study area show bulk distribution in center when plotted in A-CNK-Fm space, in contrast to laterite in Cameroon, plotting linearly in the middle along a A-FM line. Therefore, alteration of reddish saprolites in Southern Korea have not progressed as much as laterite. To define Reddish saprolite in southern Korean Peninsula as a lateritic red soil, more many studies are necessary.

Stratigraphic Analysis on Paleofluvial Outcrop underJeongok Basalt Layer in the Chugaryeong Rift Valley, Central Korea (추가령 열곡 내 전곡 현무암층 하부 고하성층 노두 층서 분석)

  • Lee, Min-Boo;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.3
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    • pp.55-63
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    • 2013
  • The study deals with the geochemical analyses on the stratigraphy and sedimentation of the paleofluvial outcrop under Jeongok basalt layer in Chugaryeong Rift Valley. The results of field survey and analysis show that the paleofluvial sand and gravel layers had been constructed before the arrival of basaltic lava in Jeongok area of Hantan River valley in central Korea. XRF, for the main elements analysis, results present that JG2-3, a test sample from basalt weathering layer, has different characteristics from 5 other samples in the aspects of chemical weathering levels. ICP-MS, for analysis of the rare earth elements analysis, estimates that gravel layer, in the lowest part of the outcrop, had been originated from pre-lava bedrocks near the upper reach of the Hantan River, so the layer is almost not related to basalt layers. Finally, the OSL dating results in paleofluvial sedimentation had been in process until nearly 40,000 BP, before formation of lava plateau in the Jeongok area.

A Relationship between Micro-Landforms and Distribution of the Ancient Dwelling Site in the Middle Western area, Korea (한반도 중서부 도서지역에 있어서 사면 미지형과 옛 주거지 분포와의 대응관계)

  • Park, Ji Hoon;Choi, Seong Gil
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.3
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    • pp.109-118
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    • 2013
  • The purpose of this study is to clarify the optimum locational environment of Neolithic Age and Bronze Age dwelling sites in Yeongjong-do, Incheon in terms of geographical characteristics. To make this possible, the micro-landform location environment of individual dwelling sites has been analyzed targeting 145 dwelling sites of Neolithic Age and 47 dwelling sites of Bronze Age in which quantitative analysis is possible among the dwelling sites verified in the investigation area until now. As a result, the micro-landform of hills where Neolithic Age and Bronze Age dwelling sites are crowded the most has been determined as the upper side hollow (64 dwelling sites, 44.1%) and the crest slope (39 dwelling sites, 83%), respectively. This means that the optimum locational environment of dwelling sites has been changed as the times have progressed from Neolithic Age to Bronze Age in the investigation area and the location of micro-landform of hills also where dwelling sites are located also has relatively moved up a little seen in terms of geographical perspective.

A study on the characteristics and geomorphic process of sand dunes at the lower reach of the Duman river, Korea and China (두만강 하류 사구지형의 특징과 형성과정에 관한 연구)

  • Zhu, Zhe;Lee, Min-Boo
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.1
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    • pp.29-40
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    • 2012
  • The sand dunes at the lower reach of the Duman river indicate that their distribution patterns and directions conform to the dominant northwestern winter wind. On the riverbed of the Duman river at the surroundings of sand dunes form sandy point bars and mid-stream islands. The geomorphic processes of sand dunes can be classified into two types according to the depositional environments via analyses of the sand grain size and stratigraphic profiles. First, the sand dunes of Hoelyongbong, Kyeongshin-Wonjeong, and the riverside areas of the Duman river, have formed by alluvium of the Duman river which deposits and accumulates on the riverbed, then being wind blown to the nearby sand bars, terraces and higher eroded hills. The second type is the active sand dune of the Bangcheon-Nodongja District which develops similarly as to the formation of the first type, but the fixed sand dunes of the district seem to have formed in the underwater condition.

Vertically Development Processes of Jangho-ri Coastal Dune, West Coast of Korea (고창 장호리 해안사구의 수직 발달 과정 연구)

  • Han, Min;Kim, Jin Cheul;Yang, Dong-Yoon;Kim, Jong Yeon
    • Journal of The Geomorphological Association of Korea
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    • v.23 no.3
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    • pp.79-92
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    • 2016
  • Samples from two boreholes of coastal dune field at Jangho-ri coast, Gochang was studied. These were analyzed by grain size analysis geochemical analysis, and the application of OSL dating method to understand the development during the Holocene. The boreholes SB8 and SB9 were classified into three different sedimentary layers by their mean grain size and geochemical characteristics. The results revealed that the upper sand layer is equivalent to the present coastal dune layer, which developed since 1,200 years ago; the silt layer in the middle to the dune slack or lagoon sedimentation layer, which developed between 1,200 and 6,000 years ago; and the sand layer at the bottom to the paleo coastal dune that developed between 6,000 and 7,000 years ago. It was proposed that the forming material of current coastal dune was supplied from the sandy flat in coastal area, while the middle silt layer was supplied from the weathered soil of a bed rock by the comparison with material of surrounding area. In the case of coastal dune, concentrated layer of sands were identified which were buried about 300 and 1,200 years ago, which is identified as the little ice age. This study confirmed the development of Jangho-ri coastal dunes after Holocene Climate Optimum period, and it is likely to assist in the understanding of coastal dunes development.