• Title/Summary/Keyword: lower terrace

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The Characteristics and Genesis of Terrace Soils in Yeongnam Area -I. Macro-Morphological Features and Soil Profile Development Index of the Terrace Soils (영남지역(嶺南地域)에 분포(分布)된 단구지토양(段丘地土壤)의 특성(特性)과 생성연구(生成硏究) -제(第) 1 보(報) 단구지토양(段丘地土壤)의 형태적특성(形態的特性)과 토양단면발달도(土壤斷面發達度))

  • Jung, Y.T.;Um, K.T.;Ha, H.S.
    • Korean Journal of Soil Science and Fertilizer
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    • v.18 no.2
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    • pp.177-188
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    • 1985
  • To clarify the characteristics and genesis of clayey terrace soils in Yeongnam area, macro-morphological features and soil profile development indexes were investigated with the sequential soils in Yeongcheon (inland region) and in Yeongil (coastal region). The results are summarized as follows; 1. According to the physiogaphy and landuse, the terrace soils were discernible to well drained yellowish red (5 YR) profile of higher terrace (Bancheon series), moderately well drained reddish yellow (7.5 YR) profile of middle terraces (Upyeong and Hwadong series), and lower terraces (Deogpyeong and Geugrag series) which were moderately well to imperfectly drained by paddy-fication. 2. The roundness and sphericity of the gravels contained in the terrace deposits were ranged around 0.543-0.546 and 0.723-0.722, respectively. The rounded to well rounded gravels were resemble to typical alluvial origins. 3. The amount of clay minerals formed in the soil horizons per 100g of parent materials were 50.8-30.7g while the rates of the clay leached were 30.1-7.4%, and the higher terrace had the more leaching rates. 4. The index of profile development of the terrace soils ranged from 37.95 to 22.01 and the index were positively correlated with relative elevations of the soils. The rates of clay leaching were positively correlated with the ratios of clay in the illuvial horizons to elluvial horizons. 5. A similarity was observed among cumulative grain size curves of the terrace soils, but the patterns of recalculated silt free cumulative grain size curve of terrace deposits in Upyeong soils in Yeongil area were abruptly different from down layer that suggest the soil to have bisequum profile.

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Distribution of Stream Incision Rates in the Northern Part of the Taebaek Mountains (태백 산지 북부의 하천 하각률 분포)

  • Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.25 no.4
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    • pp.1-19
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    • 2018
  • This study tries to identify distributional characteristics of stream incision rates at 23 points in the northern part of the Taebaek Mountains. Soyang-gang, Naerin-cheon, Odae-cheon, Dong-gang and upper reaches of Okdong-cheon Rivers closed to the Range show higher incision rates and the rates clearly decrease with distance from the Range. Therefore, the incision process in the northern part of the Range has been greatly influenced by uplift around the Range, and the Sobaek Mountain Range seem to play a role in the incision process. Limestone areas show lower incision rates due to degradation of terrace surface by dissolution. This study suggests that local hydrological, geological and geomorphological conditions can be regarded as an important factor in stream incision rates, although stream incision rates are greatly influenced by regional uplift.

Fluvial Terraces of the Lower Yeongsan River, Southwestern Coastal Region of Korean Peninsula (영산강 하류 지역의 하안단구)

  • Choi, Seong-Gil
    • The Korean Journal of Quaternary Research
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    • v.18 no.1 s.22
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    • pp.41-46
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    • 2004
  • The fluvia(thalassostatic) terraces have been developed among the lower Yeongsan river, near the southwestern coastal region of Korean peninsula. These thalassostatic terraces could be classified into 3 surface, i. e., Yeongsan 32m, 18m, and 10m surface, in desending order, according to the relative heights from the river floor. Yeongsan 32m, 18m and 10m surfaces were corresponded to the mMT3, mLT1 and mLT2 surfaces of Choi(2003), respectively. It was revealed that the mLT1 surface was the marine terraces which had been formed in the Last Interglacial culmination period(oxygen isotope stage 5e) in the southeastern coast of Korean peninsula.

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Geomorphological Processes of Fluvial Terraces at the River Basins in the East Coast in the Southern Taebaek Mountain Range (태백산맥 남부 동해안 하천 유역의 하안단구 지형 형성)

  • Lee, Gwang-Ryul
    • Journal of the Korean Geographical Society
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    • v.49 no.1
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    • pp.1-17
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    • 2014
  • This study estimates geomorphological processes of fluvial terraces by uplifts and bedrock features, by the analyses of topography, distribution, formation age and incision rate of fluvial terraces using Gwang-cheon River in Uljin, Namdae-cheon River in Pyeonghae and Osip-cheon River in Yeongdeok located in the southern Taebaek Mountain Range. The tectonic and climatic terraces I in the upper reaches of Gwang-cheon River with an altitude from riverbed of 9~12m indicate the formation age of MIS 2 with a incision rate of 0.40m/ka. However, the tectonic and climatic terraces I in the upper reaches of Osip-cheon River with an altitude from riverbed of 7~10m show the formation age of MIS 3 with an incision rate of 0.10m/ka. These results suggest that the uplift rate in the Gwang-cheon River basin is likely to be higher than that in the Osip-cheon River basin. Unlike the lower reaches of Osip-cheon River, the thalassostatic terraces are not found in the lower reaches of Gwang-cheon River, because the basin has low maintainable ability of landforms in river valley due to high uplift rate and bedrock properties resistant to weathering and erosion. On the other hand, the lowest tectonic and climatic terraces in the study areas indicate different formative ages and the terraces during the cooling stage in interglacial as well as during interstadial are also found. Therefore, this study suggests that chronological method for fluvial terrace by the previous developmental model of climatic terrace should be reconsidered.

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Physical and Acoustic Properties for Unconsolidated Sediment in the Kwangyang Bay: In Comparison with the Continental Terrace Sediment in the North Pacific (광양만 미고결 퇴적물의 물리적 및 음향학적 성질 : 북태평양 대륙붕 및 사면 자료와의 비교)

  • KIM Dae-Choul;KIM Gil-Young
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.24 no.5
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    • pp.289-302
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    • 1991
  • Laboratory determination of acoustic property for unconsolidated sediment of Kwangyang Bay was carried out. The compressional wave velocity was correlated to other physical properties and sediment textures to establish a geoacoustic model of the bay. The model was compared to the North Pacific continental terrace sediment. Velocity of the bay is systematically lower(0.02-0.04km/s) than that of the North Pacific. Average velocity of the bay is 1.521km/s. The lowest velocity is measured at the southwestern part of the bay. This area coincides with high amount of fine-grained sediment related to slower circulation. The overall tendency is, however, similar to the North Pacific continental terrace sediment.

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A Study on the Scale and Dimensions of member of Sectional structure for Five-Purlin Houses from Joseon Era (조선시대 민가 오량가(五樑架) 종단구성의 규모와 부재치수에 관한 연구)

  • Kim, Jae-Ung
    • Journal of architectural history
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    • v.28 no.1
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    • pp.7-16
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    • 2019
  • As a part of the research on existing structures of private homes from Joseon Era. Focusing on one hundred twenty five-purlin houses, the current study investigated the features and characteristics of the house structure from style, size, proportion and roof pitch, and measurements of key parts, and developed the following conclusions. Most are single-houses (89, 83%), and among them, there are 47 single front-terrace houses (39%), which is the highest number. The sizes of lower house structure do not differ greatly depending on the vertical structure, and single rear terrace house and double-house have relatively larger side sizes. The size of upper structure is larger in double-houses compared to other vertical structures, indicating a relatively higher roof. The cross-section measurement of major parts show that double-houses are larger than single-houses by 3cm in pillar, 3-4.5cm in crossbeam length, and 4.5cm in crossbeam width. However, Janghyeo width was consistent at 7.5 to 10.5cm, maintaining uniformity regardless of vertical structure of the houses. In addition, the cross-section measurements decreased from sixteenth to nineteenth century, with the size of pillar size decreasing the most. The result that the Janghyeo width is not related to the house structure house confirmed that the Janghyeo width was kept consistent regardless of the size of the house structure.

Analysis of Fluvial Terraces at Kohyun River in Youngcheon City (경북 영천시 고현천의 하안단구 지형 분석)

  • Cho, Young-Dong;Lee, Gwang-Ryul
    • Journal of the Korean Geographical Society
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    • v.44 no.4
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    • pp.447-462
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    • 2009
  • Kohyun River basin is located at southern parts of Taebaek Mountains and most of river basins consists of sedimentary rock. The aims of this study are to investigate the distribution characteristics and processes of fluvial terraces at Kohyun River, using scientific methods such as classification of fluvial landforms, analysis of geomorphological deposits, XRD and OSL age dating. In Kohyun River basin are three levels terraces from T1 to T3. Fluvial terraces are assumed to be erosional terraces according to deposited situation of alurium and existences of bedrock riverbed. From the result of OSL age dating, formation age of fluvial terrace 1(T1) is calculated about 37,000 yr.B.P.(MIS 3), and fluvial terrace 2(T2) is calculated about 113,000 yr.B.P.(MIS 5). Therefore, fluvial terraces at Kohyun River are assumed to be formed at warmer period in the glacial stages or cooler period in the interglacial stages. The incision rate of fluvial terrace 1 at Kohyun River is calculated to be 0.054m/ka, and the incision rate of fluvial terrace 2 is calculated to be 0.115m/ka. This results suggest to lower incision rate than other rivers in Korea because of low uplift rates and little discharge.

Occurrence and Identification of Tephra Layers found in the Ulsan area, Southeastern Korea (한국 동남부 울산 지역에서 발견되는 화산재층의 산상과 동정)

  • Kim, Cheong-Bin;Kim, Young-Seog;Lim, Hyoun Soo
    • Journal of the Korean earth science society
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    • v.42 no.1
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    • pp.55-64
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    • 2021
  • Tephrochronology is the study of tephra layers to correlate and date geologic events. As tephra layers can be used as time-markers, they are essential for the dating of Quaternary deposits. In this study, two types of tephra layers were found in the upper and lower parts of marine terrace deposits distributed in the Sanha-dong and Jeongja-dong, Ulsan areas. Based on the morphological features of glass shards, refractive indices, major element compositions, and similarity coefficients, the upper and lower tephras were identified as AT (ca. 25 ka) and Ata (ca. 105-110 ka) tephra, respectively. To the best of our knowledge, this is the first official report of Ata tephra on terrestrial deposits in Korea. These results are expected to aidin the research of the Quaternary paleoclimate, paleoenvironment, and active faults in the southeastern part of Korea.

Analysis of Kap-Chon's Water Level by the Waterside Planting (수변 식재에 따른 갑천의 수위 분석)

  • Woo, Won-Jae;Chung, Dong-Yang
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.1 no.1
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    • pp.3-17
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    • 1998
  • The purposes of this study is to investigate the possibility of planting trees at space land in the riverside. The space land is for the green space. Calculating the plantable space in the representation section and the flood flowing stability of the existing banks based on the hydrological and meteorological data of the Kap-Chon riverbasin located in Tae-jon, the following results are drawn. (1) The flood discharges in each flow section are $698.7m^3/s$ in section 1, $654.6m^3/s$ in section 2, and $1353.3m^3/s$ in section 3 during 100 years recurrence interval. Because the designed-flood discharges in those sections are $1719.9m^3/s$, $2119.7m^3/s$, and $1512.8m^3/s$ respectively, safety for flood flowing is sufficient in existing banks. (2) The possible clearance for planting trees is 1.80m in section 1, 3.90m in section 2, and 0.01m in section 3. Planting clearance is enough in section 1 and 2. However, planting should be planned after estimating a rise-height due to the bridge piers, because many piers under riverine-highway are now on the construction in section 2. The section 3 does not have sufficient clearance for planting trees, but the planting is possible after getting enough flow area with slope by cutting the terrace land on the river artificially heightened. (3) In case of planting a tree 70cm diameter in $1m^2$ in section 1, the water level increases by 0.60m. Planting a tree in a $48m^2$ area increases the water level by 0.90m. Considering that plantable clearance is 1.8m in section 1, it is sufficient to flow safely. But if the trees are planted so compactly from the upper stream, expected heavy resistance is expected due to caught materials on the trees. So, trees have to be planted widely in upper streams but compactedly in lower streams. (4) The river width without changing, Kap-Chon's flow channel can be snaked in accordance with the nature law the wide terrace land in the riverside. Decreased flow area due to planting trees will be compensated by the inclination of terrace land. And, it is theoretically proved that the flood discharge is safe even though the terrace land on the river is parked similar to the nature. Planting trees in the terrace land of the Kap-chon river to the extent that flood flowing is not adversely affected, we can get the enjoyable park to citizens not spending expensive cost. It also contributes to the recovery of ecosystem, which gives the natural beauty of river and shade to citizens and becomes good natural-educational places for children.

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