• Title/Summary/Keyword: Alluvial fan

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The Study of Alluvial Fans in Korea (한국(韓國) 선상지(扇狀地) 연구(硏究))

  • Park, No-Sik
    • Journal of the Speleological Society of Korea
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    • no.68
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    • pp.5-22
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    • 2005
  • Since earlier in 1947 the writer had been devoting part of his time to study alluvial fans in Korea based on his own interest in geomorphology. However, it was in 1958 when a new geography department was set up and the Research Center of National Lands was established in the university of Kyung Hee, the writer started scientific investigation for alluvial fans. The Following alluvial fans have been studied by the writer: those of Mt. Kwanak and Mt. Chungge in 1947; those of Pulkuksa in 1948; those of Suhnamsa, Suh Myun, Pusan in 1950; those of Shindonae, Mt. Kerrong, in summer of 1958; those of Hwaomsa, Kure and Yongsan Myun, Changhung, in winter of 1958. The article is the comparative study of the above mentioned alluvial fans including Suhkwangsa Fan, Chugaryng Rift Valley. Of course this is not the study covering all af alluvial fans in Korea. Within the limits of his surbey, the writer has com to a conclusion which may be helpful for the Korean alluvial fm study. 1. Korean alluvial fans are generally found in rift valleys or basins. 2. They are formed in places of below 220-meter contour line. 3. The slope from fna apex to river valley is 20-40 degree. The slope of fan surface is 5-20 degree, but most of them under 16 degree. A sudden change of slope is taken place or the fan apex and fan center. 4. Hills (100-200m) are developed on the surfaces of alluvial fans. 5. Most of rivers in alluvial fans are geyser rivers. 6. The depth of well : from ground surface to the well water surface is 4-8 m; water depth is 1-2m. 7. Land utilization; cultivated land 30%: non cultivatedland 70%. The area occupied by upland fields is twice of paddy field area. 8. Settlement : agglomerated settlement is developed on the top or the end of fan and surrounded by windbreakers. 9. Farming pattern at the top of fan fields are rectangular and parallel to flumes but at the center of fan, they are irregular and perpendicular to flumes.

The Geomorphic Development of Alluvial Fans in the Cyeongju City and Cheonbuk area, Southeastern Korea (경주 및 천북 지역의 선상지 지형발달)

  • 윤순옥;황상일
    • Journal of the Korean Geographical Society
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    • v.39 no.1
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    • pp.56-69
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    • 2004
  • We investigated the distribution and geomorphic development of alluvial fan in Gyeongju City including Cheonbuk area. According to a relative height to a river bed, alluvial fans of this area are divided into Higher surface, Middle surface, and Lower surface. As alluvial fans of Bulguk temple∼Ulsan bay area, the confluent fans in Cheonbuk and Gyeongju areas were formed by the Quaternary climatic change alternating glacial and interglacial stages, and the development of N-S and NW-SE fault lines. The Gyeongju alluvial fan, the largest in Korea, has been provided as the significant space for human activity since the prehistoric age. Bukcheon river formed the Gyeongju alluvial fan had not flowed over during the prehistoric and the ancient times. In contrast with general geomorphic characteristics, many springs in the Gyeongju alluvial fan are located in the middle part of the fan because ground water reaches to the surface. It is supposed that sedimental materials were not sufficiently piled up at lower reach of Bukcheon river due to the large deposits at upper and middle reach of the basin.

The Theoretical Study and Distributional Characteristics of Alluvial Fans in Korean Peninsula (한국 선상지의 이론적 고찰과 분포특성)

  • Saito Kyoji;Hwang Sang-Ill;Tanaka Yukiya;Oguchi Takashi;Yoon Soon-Ock
    • Journal of the Korean Geographical Society
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    • v.40 no.3 s.108
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    • pp.335-352
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    • 2005
  • The question of whether fan type surface developed at the foot of mountains is pediment or alluvial fan has been discussed consistently through the Korean geomorphic history. Unfortunately the term, 'alluvial fan' was scarcely used, also even the existence of alluvial fan has been denied throughly for a long time in Korea. The negation of alluvial fan brought some difficulties in the development of the related Geomorphology. In order to resolve such a problem, more logical and exquisite theory by examination of geomorphic process must be systematically presented on the basis of overall problem recognition. The objective of this study is to represent the theoretical indicator based on the investigation of the points at issue that the existence of alluvial fan in Korea was denied. Moreover, we selected 13 alluvial fans in southern part of Korean Peninsula to compare with the worldwide alluvial fans according to theoretical indicator, and analysed their geomorphic distributional characteristics.

The Ceomorphic Development of Alluvial Fans in Cheongdo Basin, Gyeongsangbuk-do( Prevince), South Korea (경북 청도분지의 선상지 지형발달)

  • Hwang Sang-Ill
    • Journal of the Korean Geographical Society
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    • v.39 no.4
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    • pp.514-527
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    • 2004
  • We investigated the distribution and geomorphic development of alluvial fans at Cheongdo- and Hweyang-eup(town) in the Cheongdo Basin, Gyeongsangbuk-do(Province) of Korea. The alluvial fans of study area are formed confluently to the E-W direction at the northern slope of the Mt. Namsan(840 m). They are classified into Higher surface, Middle surface, and Lower surface according to a relative height to a river bed. And the older alluvial fan is, the deeper gravel in the stream deposits is weathered. The magnitude of each surface composing of confluent fans is related to that of the drainage basin. So called fan-basin system of magnitude on the study area is on the positive(+) relation in the study area. The large fans over 1km in radius are found on the basin of andesite rock which is resistant to the weathering and erosion. Moreover there is no tectonic movement in the basin. It means the most important element influenced on the fan formation is not tectonic movement, but the Quaternary climatic change, which is the periglacial climate alternating glacial and interglacial stages during the Quaternary. Therefore alluvial fans would distribute in Korea overall influenced by the Quaternary climatic change.

A Study on the Status of Use and Value of 'Saemi' in Sacheon Alluvial Fan (사천 선상지 '새미'의 이용 실태 및 가치 고찰)

  • Kim, Dohyun;Jeong, Myeong Cheol;Seo, Ki Chun
    • Journal of the Korean Institute of Rural Architecture
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    • v.24 no.4
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    • pp.85-95
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    • 2022
  • This study is about the story of 'Saemi', existing in the Sacheon Alluvial fan area. Saemi is a local word for Dumbeong, which is the traditional water irrigation facilities in this area that could be formed according to the geographical characteristics of a Alluvial fan site. In the meantime, although Saemi has been an important source of water, related research has been mainly done from an ecological point of view. Accordingly, the researcher paid attention to the functional aspects of Saemi itself, grasped its location, distribution status, and usage including the construction method, and considered its intrinsic value through classification and characteristic analysis of Saemi. As a result of five field surveys from September 2021 to October 2022, 129 Saemies remained in the Sacheon alluvial fan area. According to the structure and shape, Saemi could be divided into basic type, complex type, and buried type. The basic type was subdivided into bucket-type and stairs-type along with the complex type, and the buried type was subdivided into all buried-type and some buried-type. Saemies were mainly distributed at the distal end of the Sacheon alluvial fan site, individual Saemies were built on farmland, and common Saemies were usually built along roadsides adjacent to villages. The reason why the Saemies are concentrated at the distal end is the geographical characteristics of the alluvial fan where the water underflows. Saemi was an important multifunctional water supply source equivalent to the main water source for people at the distal end of the pond who did not receive a stable supply of water from the reservoir. Saemi was at the center of the underground water irrigation network agricultural system in the Sacheon alluvial fan area according to the principles of 'bbaeim(drop out)' and 'gaepim(pooling)' It has provided a foundation for establishing itself as an appropriate technology in this area. Such Saemi contributed to the rural landscape and agricultural biodiversity through its own system and served as a public interest function. It is necessary to know, conserve, manage, and continuously utilize the value of this Saemi as an agricultural heritage.

The Alluvial Fan Surface Deformation of the Northern Part of the Ulsan(Bulguksa) Active Fault System in the Southeastern Korea

  • Yoon, Soon-Ock;Hwang, Sang-Il
    • The Korean Journal of Quaternary Research
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    • v.18 no.2 s.23
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    • pp.5-16
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    • 2004
  • The geomorphic deformation of the alluvial fans by tectonic movement was investigated along the lineaments of the northem part of the Ulsan(Bulguksa) fault system. Based on the aerial photographs interpretation and field surveys Ulsan fault system was identified as an active reverse fault which has displaced the Quatemary fan deposits. Buguksa fault system strikes for the direction of NW-SE and N-S. These two lineaments of active fault are crossing at Jinty village in Gyeongju city and the fault plane forms here almost vertical dip. The lateral pressures from the two directions have possibly influenced on the formation of the vertical dip at jinty villagy. It should be resulted from that the two pressures responsible for the active reverse fault at which the one with the NW-SE strike thrusts the hanging wall of Tohamsan block southwestward and the other pressure with the N-S strike thrusts it westward over the foot wall of the fan deposits. The marine oxygen isotope stage 8(0.30-0.25 Ma. BP) and stage 6(0.20-0.14 Ma. BP) are presumed to be the ages of high and middle surfaces of the alluvial fan, repectively. The vertical displacements on the high surfaces along the Bulguksa fault system are about 1.05 m at Ha-Dong, 9.5-10.5 m at Jinhyun-Dong, and about 10 m high at Jinty village. And the vertical displacement on the middle surface was measured about 6 m high at Ha-Dong. The average slip rate of vertical displacements is calculated about 0.03-0.43 mm/y.

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Irrigation Facility for Agricultural Use of Rokugo Alluvial Fan in Yokote Basin, Northeastern Japan (일본 동북지방 요코테 분지 내 로쿠고 선상지의 농업적 토지이용을 위한 관개시설 - 원통형 사이펀(siphon) 방식 분수공(分水工)을 대상으로-)

  • Kim Tae-Ho;Son Ill
    • Journal of the Korean Geographical Society
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    • v.41 no.4 s.115
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    • pp.507-512
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    • 2006
  • This paper introduces an irrigation facility for agricultural use of Rokugo alluvial fan in Yokote Basin, northeastern Japan. A cylindrical distributor of agricultural water is able to supply water accurately to seven irrigated areas through its 180 orifices and one circular baffle, implying that people around fan areas has been tenacious of agricultural water. It has been recently reevaluated as tourism resources or symbolic landscape reflecting regional characteristics even though its functional value has decreased.

Relationship of Topography and Microbial Community from Paddy Soils in Gyeongnam Province (경남지역 논 토양 지형과 미생물 군집의 관계)

  • Lee, Young-Han;Ahn, Byung-Koo;Sonn, Yeon-Kyu
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.6
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    • pp.1158-1163
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    • 2011
  • The present study was aimed to evaluate the soil microbial communities by fatty acid methyl ester (FAME) method in paddy soils at 20 sites in Gyeongnam Province. The soil microbial biomass carbon content of fan and valley $1,266mg\;kg^{-1}$ was higher than alluvial plain $578mg\;kg^{-1}$ (p<0.05). In addition, The dehydrogenase activity of fan and valley $204{\mu}g\;TPF\;g^{-1}\;24h^{-1}$ was higher than alluvial plain $93{\mu}g\;TPF\;g^{-1}\;24h^{-1}$ (p<0.05). The communities of total bacteria and Gram-negative bacteria in the fan and valley paddy soils were significantly higher than those in the alluvial plain paddy soils (p<0.05). Total bacteria communities should be considered as a potential responsible factor for the obvious microbial community differentiation that was observed between the fan and valley and alluvial plain in paddy soils.

Morphometric Characteristics of Alluvial Fans in South Korea and Comparisons with those of Japan, Taiwan and the Philippines (한반도 남부 선상지의 계량적 지형 특성과 일본, 타이완, 필리핀 선상지와의 비교 연구)

  • Yoon, Soon-Ock;Saito, Kyoji;Hwang, Sang-Ill;Oguchi, Takashi;Tanaka, Yukiya
    • Journal of the Korean Geographical Society
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    • v.45 no.4
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    • pp.431-443
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    • 2010
  • The morphometric characteristics of 13 alluvial fans in the southern parts of the Korean Peninsula are studied and relationships between their distributions and causes are discussed by comparing them with 690 alluvial fans in Japan, Taiwan and the Philippines. The relationships between the surface gradient of alluvial fans and source basin area, the surface gradient and the relief ratio of the source basin, and the source basin area and the relief ratio were investigated. The alluvial fans in South Korea have typical characteristics of the Asian fans, although their frequency and density are relatively low, and the size and the relief ratio of their source basins are relatively small and steep, respectively. Moreover 36 major Korean river basins without alluvial fans tend to have lower altitude and relief ratios. Contrary to the argument by Blair and McPherson, the natural depositional gaps on the gradient of alluvial fans were not found. The Gyeongju alluvial fan is probably a fluvial fan with gentle gradient, whereas the other Korean fans seem to be debris-flow related on the base of their gradients.

Survey of Geomorphological Resources of 'Daegu Innovation Town' Development Plan Area (대구 혁신도시 개발예정지의 지형자원 조사)

  • Son, Myoung-Won
    • Journal of the Korean association of regional geographers
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    • v.14 no.2
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    • pp.173-188
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    • 2008
  • In order to make comparative analysis of geomorphological changes caused by urban development, I surveyed the distribution of geomorphological resources of 'Daegu Innovation Town' development plan area. The results are as follow: (1) At the front of small valleys of back-mountains are formed small alluvial fans, and at the side of small valleys are distributed hills connected with back-mountains. (2) As small valley erode laterally hills, vertical bluffs and planner bedrock riverbed are formed, and in some riverbed are appeared mud cracks and ripple marks. (3) The depth of valley in alluvial fan of 'Sinseo District' is 7m. In Sinseocheon valley dissecting alluvial fan, fluvial terraces 2m high above riverbed are distributed. Those terraces were formed while alluvial fan was dissected after last glacial period.

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