• Title/Summary/Keyword: Micro-landform

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Extraction of Potential Area for Block Stream and Talus Using Spatial Integration Model (공간통합 모델을 적용한 암괴류 및 애추 지형 분포가능지 추출)

  • Lee, Seong-Ho;JANG, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.2
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    • pp.1-14
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    • 2019
  • This study analyzed the relativity between block stream and talus distributions by employing a likelihood ratio approach. Possible distribution sites for each debris slope landform were extracted by applying a spatial integration model, in which we combined fuzzy set model, Bayesian predictive model, and logistic regression model. Moreover, to verify model performance, a success rate curve was prepared by cross-validation. The results showed that elevation, slope, curvature, topographic wetness index, geology, soil drainage, and soil depth were closely related to the debris slope landform sites. In addition, all spatial integration models displayed an accuracy of over 90%. The accuracy of the distribution potential area map of the block stream was highest in the logistic regression model (93.79%). Eventually, the accuracy of the distribution potential area map of the talus was also highest in the logistic regression model (97.02%). We expect that the present results will provide essential data and propose methodologies to improve the performance of efficient and systematic micro-landform studies. Moreover, our research will potentially help to enhance field research and topographic resource management.

Analysis of Sedimentary Environment and Micro-Landform Changes Afterthe Construction of Artificial Structuresin the Tidal Flat of Anmyeondo Gagyeongju, Western Coast of Korea (인공구조물 건설 후 안면도 가경주 간석지의 퇴적환경 및 미지형변화 분석)

  • JANG, Dong-Ho;Ryu, Ju-Hyun
    • Journal of The Geomorphological Association of Korea
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    • v.25 no.1
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    • pp.31-45
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    • 2018
  • This study investigated the characteristics of sedimentary environment changes across a tidal flat in Gagyeongju of Anmyeondo Island. We performed a spatio-temporal analysis on the grain sizes composition of sediments and micro-landform changes during the winter from 2013 to 2016. The results showed that erosion was a dominant processthroughout the study flat, reducing the surface elevation even by 1 m around the upper sand flat. As a consequence, headlands have formed in the entire region of Gagyeongju village. In addition, erosion quickly progressed along the low-lying subtidal zone and tide way and, in contrast, sedimentation progressed in the mid-elevation tidal flat. We posit that a jetty, which had been constructed as a pier facility on the eastern part of the study area, interfered with the flow of tidal current, thereby enhancing these erosional processes. This is because such interference can block the supply of fine-textured sediments from the nearby Cheonsu Bay and therefore reduce surface elevation. According to the surface sediment analysis, the sediments were categorized into 7 sedimentary facies, and generally displayed a high ratio of silt and clay. The result of time-series analysis (2012-2013) showed that the sediments on the tidal flat became fine-grained, and that sorting became worse. However, the sediments on the subtidal zone, embayment and along inside of the jetty tended to be coarse-grained. In conclusion, the tidal flat microlandform change in the study area was caused by a disruption in the seawater circulation due to the jittery construction within the tidal flat, which had a direct effect on erosional and sedimentary environment processes.

Analyzing the spectral characteristic and detecting the change of tidal flat area in Seo han Bay, North Korea using satellite images and GIS (위성영상과 GIS를 이용한 북한 서한만 지역의 간석지 분광특성 및 변화 탐지)

  • Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.2
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    • pp.44-54
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    • 2005
  • In this study the tidal area in Seo han bay, North Korea was detected and extracted by using various satellite images (ASTER, KOMPSAT EOC, Landsat TM/ETM+) and GIS spatial analysis. Especially, the micro-landform was classified through the spectral characteristic of each satellite image and the change of tidal flat size was detected on passing year. For this, the spectral characteristics of eight tidal flat area in Korea, which are called as Seo han bay, Gwang ryang bay, Hae iu bay, Gang hwa bay, A san bay, Garorim bay, Jul po bay and Soon chun bay, were analyzed by using multi band of multi spectral satellite images such as Landsat TM/ETM+. Moreover, the micro-landform tidal flat in Seo han bay, North Korea was extracted by using ISODATA clustering based on the result of spectral characteristic. In addition, in order to detect the change of tidal flat size on passing years, the ancient topography map (1918-1920) was constructed as GIS DB. Also, the tidal flat distribution map based on the temporal satellite images were constructed to detect the tidal flat size for recent years. Through this, the efficient band to classify the micro-landform and detect its boundary was clarified and one possibility of KOMPSAT EOC application could be also introduced by extracting the spatial information of tidal flat efficiently.

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The Optimal Location Environment of the Bronze Age Settlement in Yongdu Stream and its Surrounding Area in Asan through the Ridge Environment's Perspective (능선환경으로 본 아산 용두천 유역 및 주변 지역에 있어서 청동기시대 취락의 최적 입지환경)

  • Park, Ji Hoon;Lee, Ae Jin
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.4
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    • pp.89-112
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    • 2020
  • The purpose of this study is as follows: First, we restore the optimal topographical environment of the Bronze Age settlements in the Yongdu Stream and its surrounding area in Asan City. Second, we reveal the relative importance of the topographical factors that the Bronze Age people considered when selecting their dwelling locations. We compared and analyzed topographical factors (ridge scale, ridge direction, slope direction of the ridge, micro-landform of the ridge, position of the ridge) from the ridge's environmental perspective of 123 Bronze Age dwellings (hereinafter referred to as dwellings) found in the survey area for that purpose. The results are as follows: First, from a macro perspective, the optimal topographical environment for the location of the Bronze Age settlement is the second ridge that have the E-W direction. And from a micro perspective, it is the southeast direction slope of the Crest slope at the summit. Second, it appears that the Bronze Age people have taken important consideration in determining the location of their dwelling in the following order: ① position (eg. summit), ② micro-landform (eg. Crest slope, Upper slope), ③ slope direction (eg. southward, South, Southeast), ④ scale (eg. sub-ridge, secondary, tertiary), ⑤ direction (eg. E-W, NNE-SSE).

Analysis of Geomorphological Environment forthe Jar Coffins Location in the Yeongsan River Basin in Jeonnam Province (전남 영산강 유역에 있어서 옹관묘 입지의 지형환경 분석)

  • Park, Ji Hoon;Lee, Chan Hee
    • Journal of The Geomorphological Association of Korea
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    • v.23 no.3
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    • pp.13-25
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    • 2016
  • The purpose of this study is to investigate the location characteristics in which 'large Jar coffin' (hereinafter referred to as 'Jar coffin') distributed in the Yeongsan river basin area in Jeonnam province by means of topographic analysis. 75 Jar coffins (74.3%) in 19 relics (90.5% of total) were found in hill and 26 Jar coffins (25.7%) of two consumption relics (9.5%) were found in floodplain. Among them, 34 (45.3% of total) and 41 (54.7% of total) Jar coffins were found in the Crest surface and Sideslope of hills, respectively. In particular, 26 (34.7%) Jar coffins are mostly located in the Crest flat. This result implies that people at that might be consider the river inundation, and mostly choose hill rather than floodplain when building the Jar coffin. therefore amongtherefore among micro-landform units of the hill, it seems that the 'Crest flat' was the preferred place for the building the Jar coffin at that time.

Property Analyses of Deposits and Landform in Tidal Flat using Satellite Image

  • Jo, Myung-Hee;Sugimori, Yasuhiro;Jo, Wha-Ryong
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.110-115
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    • 1998
  • Through the ISODATA method, the micro-landform of Julpo-Bay tidal flat was classified into mudflat, mixedflat, and sandflat using Landsat TM image. Each showed an apparent differences in its topographical characteristics and grain size composition. For example, mudflats are formed with flat faces and tidal channel of dissected gully. Its characteristics of grain size analysis that the grains have less than mean grain size 4 phi. Its sorting is bad (higher than 1 S.D.), and it showed strongly positive skewness. But sandflat is topographically flat without tidal channel. It has developed with ripple marks. According to the grain size analysis of deposits, the soil is coarse size with 90% of sand and its sorting is well(lower than 1 S.D.) Also, it showed strongly negative skewness. Mixed flat is in between mudflat and sandflat in its characteristics.

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한강하류지형면의 분류와 지형발달에 대한 연구 (양수리에서 능곡까지)

  • Park, No-Sik
    • Journal of the Speleological Society of Korea
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    • no.68
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    • pp.23-73
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    • 2005
  • Purpose of study; The purpose of this study is specifically classified as two parts. The one is to attempt the chronological annals of Quaternary topographic surface through the study over the formation process of alluvial surfaces in our country, setting forth the alluvial surfaces lower-parts of Han River area, as the basic deposit, and comparing it to the marginal landform surfaces. The other is to attempt the classification of micro morphology based on the and condition premising the land use as a link for the regional development in the lower-parts of Han river area. Reasons why selected the Lower-parts of Han river area as study objects: 1. The change of river course in this area is very serve both in vertical and horizontal sides. With a situation it is very easy to know about the old geography related to the formation process of topography. 2. The component materials of gravel, sand, silt and clay are deposited in this area. Making it the available data, it is possible to consider about not oかy the formation process of topography but alsoon the development history to some extent. 3. The earthen vessel, a fossil shell fish, bone, cnarcoal and sea-weed are included in the alluvial deposition in this area. These can be also valuable data related to the chronological annals. 4. The bottom set conglometate beds is also included in the alluvial deposits. This can be also valuable data related to the research of geomorphological development. 5. Around of this area the medium landform surface, lower landform surface, pediment and basin, are existed, and these enable the comparison between the erosion surfaces and the alluvial surfaces. Approach : 1. Referring to the change of river beds, I have calculated the vertical and horizontal differences comparing the topographic map published in 1916 with that published in 1966 and through the field work 2. In classifying the landform, I have applied the method of micro morphological classification in accordance with the synthetic index based upon the land conditions, and furthermore used the classification method comparing the topographic map published in 1916 and in that of 1966. 3. I have accorded this classification with the classification by mapping through appliying the method of classification in the development history for the field work making the component materials as the available data. 4. I have used the component materials, which were picked up form the outcrop of 10 places and bored at 5 places, as the available data. 5. I have referred to Hydrological survey data of the ministry of Construction (since 1916) on the overflow of Han-river, and used geologic map of Seoul metropolitan area. Survey Data, and general map published in 1916 by the Japanese Army Survbey Dept., and map published in 1966 by the Construction Research Laboratory and ROK Army Survey Dept., respectively. Conclusion: 1. Classification of Morphology: I have added the historical consideration for development, making the component materials and fossil as the data, to the typical consideration in accordance with the map of summit level, reliefe and slope distribution. In connection with the erosion surface, I have divided into three classification such as high, medium and low-,level landform surfaces which were classified as high and low level landform surfaces in past. furthermore I have divided the low level landform surface two parts, namely upper-parts(200-300m) and bellow-parts(${\pm}100m$). Accordingly, we can recognize the three-parts of erosion surface including the medium level landform surface (500-600m) in this area. (see table 22). In condition with the alluvial surfaces I have classified as two landform surfaces (old and new) which was regarded as one face in past. Meamwhile, under the premise of land use, the synthetic, micro morphological classification based upon the land condition is as per the draw No. 19-1. This is the quite new method of classification which was at first attempted in this country. 2. I have learned that the change of river was most severe at seeing the river meandering rate from Dangjung-ni to Nanjido. As you seee the table and the vertical and horizontal change of river beds is justly proportionable to the river meandering rate. 3. It can be learned at seeing the analysis of component materials of alluvial deposits that the component from each other by areas, however, in the deposits relationship upper stream, and between upper parts and below parts I couldn't always find out the regular ones. 4. Having earthern vessel, shell bone, fossil charcoal and and seaweeds includen in the component materials such as gravel, clay, sand and silt in Dukso and Songpa deposits area. I have become to attempt the compilation of chronicle as yon see in the table 22. 5. In according to hearing of basemen excavation, the bottom set conglomerate beds of Dukso beds of Dukso-beds is 7m and Songpa-beds is 10m. In according to information of dredger it is approx. 20m in the down stream. 6. Making these two beds as the standard beds, I have compared it to other beds. 7 The coarse sand beds which is covering the clay-beds of Dukso-beds and Nanjidobeds is shown the existence of so-called erosion period which formed the gap among the alluvial deposits of stratum. The former has been proved by the sorting, bedding and roundness which was supplied by the main stream and later by the branch stream, respectively. 8. If the clay-beds of Dukeo-bed and Songpa-bed is called as being transgressive overlap, by the Eustatic movement after glacial age, the bottom set conglomerate beds shall be called as being regressive overlap at the holocene. This has the closest relationship with the basin formation movement of Seoul besides the Eustatic movement. 9. The silt-beds which is the main component of deposits of flood plain, is regarded as being deposited at the Holocene in the comb ceramic and plain pottery ages. This has the closest relationship with the change of river course and river beds.

Dwelling Site of 'Cheonan Baekseokdong Relic Group' Using GIS Analysis - Paying Attention to the Gradient of Each of Micro-Landforms of Hillslope - (GIS분석을 이용한 천안 백석동유적그룹의 청동기시대 주거지 입지의 최적 지형환경 - 구릉사면의 미지형별 경사도에 주목하여 -)

  • PARK, Ji-Hoon;PARK, Jong-Chul
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.1
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    • pp.85-100
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    • 2011
  • We were to investigate the geomorphological environment of optimum location in the object of Bronze Age's dwelling site (hereinafter called dwelling site) of total of 205 units confirmed in the 'Cheonan Baekseokdong Relic Group' distributed in hill of the uppermost stream part in the watershed of Jangjae stream in Cheonan, Chungnam Province. To do this, we classified the hill of the object of investigation where dwelling sites were distributed as 8 units of slope micro-landforms and again by combining them with the grade of gradient of 5 units subdivided them into ultra-micro-landforms of total 40 units. On the foundation of this, in the viewpoints of 'gradients of each of micro-landforms' analyzed the 'number of dwelling sites' and 'dwelling site distribution density (measure: number of dwelling sites/1000m2) of 'Cheonan Baekseokdong Relic Group'. As the result, the optimum landform environment where the dwelling sites were located were found to be largely 5 units of ultra-micro-landforms - ① flat land of crest flat, ② gentle slope land of crest flat, ③ flat land of crest slope, ④ gentle slope land of crest slope and ⑤ semi-gentle slope land of crest slope. This analyzed material will be used from now on as basic material which can predict the distribution of dwelling sites of Bronze Age men who dwelled in the watershed of Jangjae stream.

Behaviour of Subsurface Water Flow on the 'U-shaped Gol' Head Hollow of Hillslope (호우시 구릉지 완사면에 발달된 'U자골' 곡두부에서의 지중수 거동)

  • Cho, Kyong-Min;Yang, Hea-Kun;Astunao, Marui;Park, Jong-Kwan
    • Journal of the Korean Geographical Society
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    • v.41 no.6 s.117
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    • pp.670-681
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    • 2006
  • The purpose of this study is to clarify the behavior of subsurface water flow during rainfall on the hillslope in the Dongguneung experimental basin. As a result of the study, the following conclusions were obtained. Under the total rainfall of 20mm, there were no groundwater level changes. However, it was found that total rainfall amount and rainfall intensity were important factors to change groundwater level in hilly slope. Also the rainfall duration and preexisted rainfall amount were important factors to change it on the head hollow. To analyze the modification of 'U-shaped Gol' landform, the pattern of return flow and through flow have to check during storm events. The microgeomorphic change of head hollow is based on the pattern of subsurface water flow.

Landform Changes of Terminal Area of the Nagdong River Delta, Korea (낙동강 삼각주 말단의 지형 변화)

  • 오건환
    • The Korean Journal of Quaternary Research
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    • v.13 no.1
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    • pp.67-78
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    • 1999
  • In present, the terminal area of the Nagdong River Delta consists of micro-depositional landforms with sand barrier islands, sand bars and tidal flats which are arranged parallel to the present shoreline, and have rapidly shifted toward sea during last 100 years due to human activities such as construction of estuary dam, industrial complex and residential area. To clarify the landform changes of the area, the author traced the morphologic change pattern based on interpretation of air-photos, topographic maps and old Korean traditional map, and the results are as follows ; Based on the Daedongyeojido, one of the old Korean map, published in 1861, the area including upper part of the delta was underlying by sea level except two larger sand barriers, which means the Nagdong River Delta was not completely formed as the present outline of morphology by 1860s. According to the topographic map(1 :50,000) of 1916, the delta resembled to the present morphology pattern was exposed in 1916, and at this time the area was mainly composed of one sand barrier island, four sand bars and tidal flats, which had slowly elongated southwards before construction of the Nagdong River Estuary Dam in 1987. But after 1987, the area has been rapidly and drastically shifted southwards in arrange with one chain of sand barrier islands (Elsugdo -Myeonghodo-Sinhodo ) and four chains of sand bars (first chain ; Jinwoodo -Daemadeung-Maenggeummeorideung, second chain : Jangjado-Baeghabdeung, third chain ; Saedeung-Namusitdeung, fourth : Doyodeung-Dadaedeung) parallel to shoreline. This rapid landform change of the area is now occurring, and is seemed to ascribed firstly, to the construction of the Nagdong River Estuary Dam on Elsugdo in 1987, the Sinho Industrial Complex on Sinhodo and Myeongji Residential Area on Myeonghodo in 1992, secondly, to artificial alteration of drainage channel and consequential breakdown of former energy system between riverflow and tidal-and wave-energy. From these facts, it is inferred that the landform change pattern of the area will continue until a new equilibrium between the factor available to this energy system is accomplished.

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