• Title/Summary/Keyword: talus slope

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The Study on the Debris Slope Landform in the Southern Taebaek Mountains (태백산맥 남부산지의 암설사면지형)

  • Jeon, Young-Gweon
    • Journal of the Korean Geographical Society
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    • v.28 no.2
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    • pp.77-98
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    • 1993
  • The intent of this study is to analyze the characteristics of distribution, patter, and deposits of the exposed debris slope landform by aerial photography interpretation, measure-ment on the topographical maps and field surveys in the southern part Taebaek mountains. It also aims to research the arrangement types of mountain slope and the landform development of debris slopes in this area. In conclusion, main observations can be summed up as follows. 1. The distribution characteristics 1)From the viewpoint of bedrocks, the distribution density of talus is high in case of the bedrock with high density of joints, sheeting structures and hard rocks, but that of the block stream is high in case of intrusive rocks with the talus line. 2)From the viewpoint of bedrocks, the distribution density of talus is high in case of the bedrock with high density of joints, sheeting structures and hard rocks, but that of the block stream is high in case of inrtusive rocks with the talus line. 2) From the viewpoint of distribution altitude, talus is mainly distributed in the 301~500 meters part above the sea level, while the block stream is distributed in the 101~300 meters part. 3) From the viewpoint of slope oriention, the distribution density of talus on the slope facing the south(S, SE, SW) is a little higher than that of talus on the slope facing the north(N, NE, NW). 2. The Pattern Characteristics 1) The tongue-shaped type among the four types is the most in number. 2) The average length of talus slope is 99 meters, especially that of talus composed of hornfels or granodiorite is longer. Foth the former is easy to make free face; the latter is easdy to produce round stones. The average length of block stream slope is 145 meters, the longest of all is one km(granodiorite). 3) The gradient of talus slope is 20~45${^\circ}$, most of them 26-30${^\croc}$; but talus composed of intrusive rocks is gentle. 4) The slope pattern of talus shows concave slope, which means readjustment of constituent debris. Some of the block stream slope patterns show concave slope at the upper slope and the lower slope, but convex slope at the middle slope; others have uneven slope. 3. The deposit characteristics 1) The average length of constituent debris is 48~172 centimeters in diameter, the sorting of debris is not bad without matrix. That of block stream is longer than that of talus; this difference of debris average diameter is funda-mentally caused by joint space of bedrocks. 2) The shape of constituent debris in talus is mainly angular, but that of the debris composed of intrusive rocks is sub-angular. The shape of constituent debris in block stream is mainly sub-roundl. 3) IN case dof talus, debris diameter is generally increasing with downward slope, but some of them are disordered and the debris diameter of the sides are larger than that of the middle part on a landform surface. In block stream, debris diameter variation is perpendicularly disordered, and the debris diameter of the middle part is generally larger than that of the sides on a landform surface. 4)The long axis orientation of debris is a not bad at the lower part of the slope in talus (only 2 of 6 talus). In block stream(2 of 3), one is good in sorting; another is not bad. The researcher thinks that the latter was caused by the collapse of constituent debris. 5) Most debris were weathered and some are secondly weathered in situ, but talus composed of fresh debris is developing. 4. The landform development of debris slopes and the arrangement types of the mountain slope 1) The formation and development period of talus is divided into two periods. The first period is formation period of talus9the last glacial period), the second period is adjustment period(postglacial age). And that of block stream is divided into three periods: the first period is production period of blocks(tertiary, interglacial period), the second formation period of block stream(the last glacial period), and the third adjustment period of block stream(postglacialage). 2) The arrangement types of mountain slope are divided into six types in this research area, which are as follows. Type I; high level convex slope-free face-talus-block stream-alluvial surface Type II: high level convex slope-free face-talus-alluvial surface Type III: free face-talus-block stream-all-uvial surface Type IV: free face-talus-alluval surface Type V: talus-alluval surface Type VI: block stream-alluvial surface Particularly, type IV id\s basic type of all; others are modified ones.

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Preservation and Management Plan through the Analysis of Plant Resources and Functions of Algific Talus Slope as a Climate Change Shelter (기후변화 피난처로서 풍혈지의 식물자원 및 기능 분석을 통한 보전 및 관리방안)

  • Tae-Young Hwang;Jong-Won Lee;Ho-Geun Yun;Wan-Geun Park;Jong-Bin An
    • Korean Journal of Plant Resources
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    • v.36 no.2
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    • pp.133-171
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    • 2023
  • This study was conducted to prepare basic data by analyzing the biological values and environmental factors of algific talus slope in order to respond to climate change due to the greenhouse effect, and to establish plans for forest biodiversity preserving and managing. Meteorological information was measured and the flora of vascular plants were investigated for six algific talus slope by seasonally from 2020 to 2021. As a result of the investigation, the temperature of all 6 algific talus slope was lower than that of the area where the algific talus slope was located in summer, and flora was 101 families, 350 genera, 621 species, 18 subspecies, 57 variants, 7 varieties, 703 taxa. In sum, it is judged that the algific talus slope has sufficient reasons and value to be preserved because it has excellent micrometeorological value from the cold wind blowing in summer and phytogeographical value in which various plants live in a small area. However, in spite of such an important area, the management of algific talus slope is insufficient, and the algific talus slope is damaged or the ecosystem of the algific talus slope is disturbed. Therefore, it is necessary to establish a systematic conservation and management plan by designating algific talus slope as a forest genetic resource reserve and OECM.

Wetness Index Estimate and Suggestion of the Criteria of the Rockfall Protective Barrier in Talus slope (테일러스 사면의 습윤지수 산정 및 낙석방호시설 설치 기준 제안)

  • Kim, Seung-Hyun;Koo, Ho-Bon;Baek, Yong;Kim, Sung-Wook;Kim, In-Soo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.592-599
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    • 2004
  • Talus topography is that weathered rock clasts were accumulated dropping in steep slope to action of gravity. Rock fall talus is formed by the accumulation of rock debris falling as individual particles from a cliff. If the collapse is produced in talus slope. it will be possible the loss of manpower and country. Despite correct access about talus is required, domestic research was scientific access about talus short because of short resolution of aerophoto and difficulties of research about huge talus. In this Study, Our research team analgize the wetness index using the geomorphogical data. Lineament through wetness index is simillar with distribution of the talus. And, the aim of the present study is to review and compare fabric data derived from rock fall talus about orientation, distribution and morphology. These deposits tend to have approximately equal amounts of clasts oriented parallel and perpendicular to the dip direction of the slope. And, platy- shaped clasts dominate the proximal and intermediate parts of the talus, wheres blocky-shaped clasts is more common in the distal part. we carry out Rock Fall Simulation. And, We install criteria of the rockfall protective barrier using talus and geomorphological characteristics.

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A study on Orientation and Morphology of clasts in Rockfall Talus in the Sukam area, Bukpyoung-eup, Gangwon-do, South Korea (테일러스 역의 방향성 및 형태 분포에 대한 연구 - 강원도 정선군 북평읍 숙암리 지내 사면을 중심으로 -)

  • Kim, Seung-Hyun;Koo, Ho-Bon;Baek, Yong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.469-474
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    • 2003
  • Talus topography is that rock clasts that is weathered is accumulated dropping in steep slope to action of gravity. Rock fall talus is formed by the accumulation of rock debris falling as individual particles from a cliff. If the collapse is produced in talus slope, it will be possible the loss of manpower and country. Despite correct access about talus is required, domestic research was scientific access about talus short. The aim of the present study is to review and compare fabric data derived from rock fall talus about orientation, distribution and morphology in Sukam area. These deposits tend to have approximately equal amounts of clasts oriented parallel and perpendicular to the dip direction of the slope. And, platy-shaped clasts dominate the proximal and intermediate parts of the talus, whereas blocky-shaped clasts is more common in the distal part.

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Water-induced changes in mechanical parameters of soil-rock mixture and their effect on talus slope stability

  • Xing, Haofeng;Liu, Liangliang;Luo, Yong
    • Geomechanics and Engineering
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    • v.18 no.4
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    • pp.353-362
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    • 2019
  • Soil-rock mixture (S-RM) is an inhomogeneous geomaterial that is widely encountered in nature. The mechanical and physical properties of S-RM are important factors contributing towards different deformation characteristics and unstable modes of the talus slope. In this paper, the equivalent substitution method was employed for the preparation of S-RM test samples, and large-scale triaxial laboratory tests were conducted to investigate their mechanical parameters by varying the water content and confining pressure. Additionally, a simplified geological model based on the finite element method was established to compare the stability of talus slopes with different strength parameters and in different excavation and support processes. The results showed that the S-RM samples exhibit slight strain softening and strain hardening under low and high water content, respectively. The water content of S-RM also had an effect on decreasing strength parameters, with the decrease in magnitude of the cohesive force and internal friction angle being mainly influenced by the low and high water content, respectively. The stability of talus slope decreased with a decrease in the cohesion force and internal friction angle, thereby creating a new shallow slip surface. Since the excavation of toe of the slope for road construction can easily cause a landslide, anti-slide piles can be used to effectively improve the slope stability, especially for shallow excavations. But the efficacy of anti-slide piles gradually decreases with increasing water content. This paper can act as a reference for the selection of strength parameters of S-RM and provide an analysis of the instability of the talus slope.

The Distribution Characteristics Analysis of Block Stream and Talus Landform by Using GIS-based Likelihood Ratio in the Honam Region (GIS 기반 우도비를 이용한 호남지역 암괴류와 애추지형의 분포 특성 분석)

  • JANG, Dong-Ho;Kim, ChanSoo
    • Journal of The Geomorphological Association of Korea
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    • v.25 no.2
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    • pp.1-14
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    • 2018
  • The main objective of this paper is to classify properties of the locational environment for each debris type by calculating likelihood ratio based on the correlation between the distributions for each type of debris landform. A total of 8 thematic maps, like as elevation, slope, aspect, curvature, topographic wetness index (TWI), soil drainage, geology, and landcover including with GIS spatial information generally used in this type of debris landform analysis. The results of this study showed that the block stream had a high likelihood ratio compared to talus in areas with relatively high elevation; and concerning slope, the block stream had a high likelihood ratio in a relatively low region than talus. Concerning aspect, a clear correlation could not be analyzed for each debristype, and concerning curvature, the block stream displayed a developed slope on the more concave valley than the talus. Analysis concerning TWI, the block stream displayed a higher likelihood ratio in wider sections than talus, and concerning soil drainage, the talus and block stream both displayed a high likelihood ratio in regions with well-drained soil. The talus displayed a high likelihood ratio in the order of metamorphic rocks, sedimentary rocks, and granite, while the block stream displayed a high likelihood ratio in the order of volcanic rocks, granite, and sedimentary rocks. In addition, concerning landcover, the likelihood ratio had the most concentrated distributed compared to natural bare land only concerning talus. Based on the likelihood ratio result, it can be used as basic data for extracting the possible areas of distribution for each debris type through the GIS spatial integration method.

Geomorphic Features of ${\check{O}}rumkol$(Frozen Valley) Area (Kyungnam Province, South Korea) - Mainly about Talus - (경남 밀양 얼음골 일대의 지형적 특성 -Talus를 중심으로-)

  • Jeon, Young-Gweon
    • Journal of the Korean association of regional geographers
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    • v.3 no.1
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    • pp.165-182
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    • 1997
  • The aim of this paper is to clarify geomorphic features on talus within ${\check{O}}rumkol$ and the origin of ${\check{O}}rumkol$. ${\check{O}}rumkol$ is located in Milyang of Kyungnam province, in South Korea. ${\check{O}}rumkol$ is good area to study talus. because it is characterized by following three geomorphic landscapes : free face surrounding ${\check{O}}rumkol$ ; ${\check{O}}rumkol$ with deep and wide valley floor ; lots of taluses typically developing within ${\check{O}}rumkol$. The main results can be summarized as follows: 1) The origin of ${\check{O}}rumkol$ may be suggested two assumptions : one is that its origin have been resulted from intrusion structure(intrusive rock might capture less resistant rock as tuff) ; the other is that its origin have been resulted from volcanic depression after intrusion or eruption. But these assumptions are not obvious. therefore more geological evidences will be supplemented after this 2) The characteristics of ${\check{O}}rumkol$ talus (1) Pattern ${\check{O}}rumkol$ taluses are tongue-shaped or cone-shaped in appearance. They are $50{\sim}200m$ in length and the range of the maximum width from 25 to 115m and one of their mean slope gradient from 32 to $36^{\circ}$ (2) Origin ${\check{O}}rumkol$ taluses have been formed under periglacial environment in the last glacial age and they are classified into rock fall talus type, considering in conjunction with the shape, hardness, sorting, weathering conditions of constituent debris. (3) The stage of landform development ${\check{O}}rumkol$ talus slope profiles are mainly concave slope. This concave slope type was eventually caused by talus creep at the lower end of the talus. That means new additions of debris from the free face have virtually ceased and there is no evidence of recent motion in the deposit. Now it is predominant that vegetation cover is gradually increasingly. Therefore ${\check{O}}rumkol$ taluses appear to be relict form stage. at present.

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The First Finding of the Lichen Solorina saccata at an Algific Talus Slope in Korea

  • Park, Jung Shin;Kim, Dong-Kap;Kim, Chang Sun;Oh, Seunghwan;Kim, Kwang-Hyung;Oh, Soon-Ok
    • Mycobiology
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    • v.48 no.4
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    • pp.276-287
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    • 2020
  • An algific talus slope is composed of broken rocks with vents connected to an ice cave, releasing cool air in summer and relatively warmer air in winter to maintain a more stable microclimate all year round. Such geological features create a very unusual and delicate ecosystem. Although there are around 25 major algific talus slopes in Korea, lichen ecology of these areas had not been investigated to date. In this study, we report the first exploration of lichen diversity and ecology at an algific talus slope, Jangyeol-ri, in Korea. A total of 37 specimens were collected over 2017-2018. Morphological and sequencing analysis revealed 27 species belonging to 18 genera present in the area. Of particular interest among these species was Solorina saccata, as it has previously not been reported in Korea and most members of genus Solorina are known to inhabit alpine regions of the Northern Hemisphere. We provide here a taxonomic key for S. saccata alongside molecular phylogenetic analyses and prediction of potential habitats in South Korea. Furthermore, regions in South Korea potentially suitable for Solorina spp. were predicted based on climatic features of known habitats around the globe. Our results showed that the suitable areas are mostly at high altitudes in mountainous areas where the annual temperature range does not exceed 26.6 ℃. Further survey of other environmental conditions determining the suitability of Solorina spp. should lead to a more precise prediction of suitable habitats and trace the origin of Solorina spp. in Korea.

Thermal Regime of a Cold Talus Slope in Uiseong Binggye-ri Ice Valley, Korea (의성 빙계리 얼음골의 저온 현상에 관한 연구)

  • Seo, Kwang-Su;Hwang, Soo-Jin
    • Journal of Environmental Science International
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    • v.27 no.3
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    • pp.155-165
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    • 2018
  • Observations were conducted in Uiseong Binggye-ri Ice Valley of Korea, where a low temperature talus is located. The talus temperature at Ice Hole near the lower end of the talus remained at $0^{\circ}C$ until summer or autumn and averaged $-0.3^{\circ}C$ over 2 years. The talus temperature at Warm Hole was much higher than the external air temperature during autumn and winter. The outflow of warm air at Warm Hole begins in the late summer of fall. The direction of airflow through the talus surface was determined by the relationship between talus temperature and external air temperature. Annual variations in talus temperature and air exchange between the talus and the external environment can be divided into four periods. It was found that the airflow directions at Warm Hole and Ice Hole were not necessarily opposites. The outflows from the talus at Ice Hole and Warm Hole can occur simultaneously.