• Title/Summary/Keyword: 한국 지형학회

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Development of Depositional Landforms in Upstream Reach of Ulsan Sayeon Dam Lake (울산 사연호 상류의 퇴적지형 발달)

  • Chang, Mun-Gi
    • Journal of the Korean association of regional geographers
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    • v.13 no.4
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    • pp.409-421
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    • 2007
  • The purpose of this paper is to consider the formation processes and depositional conditions of bars formed at the upper-stream part of Sayeon Dam since Sayeon Dam construction in 1964. Results of analyzing the shape characteristics of bars and their sediment grain size distribution are as follow: Firstly, bars are able to categorized as subaqueous bars (A, B), mid-channel bars(C, D), and tributary side-bars(E). Secondly, the outline of bars has longish along the flow path, and their height lowers more and more going towards downstream. Also the height of bar surface tend to heighten from flow path to mountain slope. However, the near part of A is comparatively higher than its distant part, A is defined as a subaqueous natural levee and back swamp. Thirdly, the average particle size of A and B become smaller toward mountain slope. In transportation style, ratio of suspended load become higher toward mountain slope. Fourthly, sorting is worse to very worse according with lake's random changable water level. Fifthly, bar A and B were formed by vertical sedimentation of sediments according as sediments transported along flow path in the subaqueous conditions were spreaded out of flow path. C and D were formed by bed load as flood level lowered. And E was formed by vertical sedimentation while stream flow stopped in tributary's mouth areas with the water level heightening.

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GIS-based Analysis of Debris-flow Characteristics in Gangwon-do (GIS를 이용한 강원지역 토석류 특성분석)

  • Ko, Suk Min;Lee, Seung Woo;Yune, Chan Young;Kim, Gi Hong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.1
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    • pp.57-67
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    • 2013
  • In Korea, there are debris-flow disasters induced by typhoon and localized torrential rainfall annually. There are particularly extensive debris-flow disasters in Gangwon-do because of its geomorphological characteristics; the extensive coverage of mountainous region, steep slope, and shallow soil. In this paper, we constructed a GIS database about topological characteristics of debris-flow basin in Gangwon-do by years of field survey. Also, we conducted frequency analysis based on this database with the digital forest type map and the digital soil map. We analyzed frequencies of debris-flow by simple count for topological characteristics, whereas we analyzed by considering an area ratio based on GIS for physiognomic and geologic characteristics. We used slope, aspect, width, depth and destruction shapes for analysis about topological characteristics of debris-flow basin. Also we used attributes of forest physiognomy, diameter, age, and density about physiognomic characteristics, and i n terms of geologic characteristics, we used attributes of drainage class, effective soil depth, subsoil properties, subsoil grave content, erosion class, parent material of soil, and topsoil properties. In consequence, we figured out topographic, forest physiognomic, and geologic characteristics of debris-flow basin. This result is applicable to establish a rational disaster prevention policy as a fundamental information.

Effect of Direct Solar Radiation with Sloped Topography in a Mesoscale Meteorological Model (중규모 기상모형에서 지표면 경사를 고려한 직달 복사량의 효과)

  • Shin, Sun-Hee;Lee, Young-Sun;Ha, Kyung-Ja
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.4
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    • pp.45-59
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    • 2006
  • In this study, the effects of the surface topographical characteristics on the meteorological fields are examined in a mesoscale meteorlolgical model. We calculated the direct solar radiation using the illumination angle considering the inclination of topography and tried to find out its effect on meteorological fields. In above experiments, we selected two cases for the clear day and the cloudy day to show the effect of weather and represented the results for two cases. In the correction of the direct solar radiation, the results of two cases indicate that there are obvious differences on the steep Taeback and Soback mountains. And on the time-series analysis the east-facing slope of these mountains receives the more direct solar radiation about $10-60W/m^2$ in the morning hours but lesser in the afternoon hours than the horizontal surface while it is opposite on the west-facing slope. And the results mentioned above are more obvious at clear day. With the same analysis method, at clear day, the surface skin temperature is higher at all hours than that on horizontal surface on the both of slope. At cloudy and rainy day, the surface skin temperature on the east-facing slope is higher in the morning hours but lower in the afternoon hours than that on horizontal surface. But on the west-facing slope, it is higher at all hours than that on horizontal surface. In the two cases, the temperature considering the slope of surface is almost higher than that on the horizontal surface. The wind is stronger than that on the horizontal surface with increasing pressure gradient force according as increasing temperature gradient around the Taeback and the Soback mountains.

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Development of the Visualization Prototype of Radar Rainfall Data Using the Unity 3D Engine (Unity 3D 엔진을 활용한 강우레이더 자료 시각화 프로토타입 개발)

  • CHOI, Hyeoung-Wook;KANG, Soo-Myung;KIM, Kyung-Jun;KIM, Dong-Young;CHOUNG, Yun-Jae
    • Journal of the Korean Association of Geographic Information Studies
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    • v.18 no.4
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    • pp.131-144
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    • 2015
  • This research proposes a prototype for visualizing radar rainfall data using the unity 3D engine. The mashup of radar data with topographic information is necessary for the 3D visualization of the radar data with high quality. However, the mashup of a huge amount of radar data and topographic data causes the overload of data processing and low quality of the visualization results. This research utilized the Unitiy 3D engine, a widely used engine in the game industry, for visualizing the 3D topographic data such as the satellite imagery/the DEM(Digital Elevation Model) and radar rainfall data. The satellite image segmentation technique and the image texture layer mashup technique are employed to construct the 3D visualization system prototype based on the topographic information. The developed protype will be applied to the disaster-prevention works by providing the radar rainfall data with the 3D visualization based on the topographic information.

Analysis of the Geomorphological Environments of High-Density Residential Zone in Bronze Age around Asan City, Central Korea - A Case Study of Yongdoocheon and Onyangcheon Basin - (충남 아산의 청동기 시대 주거지 밀집 구역의 지형환경 분석 - 용두천과 온양천 유역을 사례로 -)

  • Park, Ji-Hoon;Park, Jong-Chul
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.3
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    • pp.110-125
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    • 2011
  • A number of the Bronze Age dwelling sites have been found and excavated in the Yoodoocheon, Onyangcheon and Baekseokdong basins. Two basins are located near Asan and Onyan in the Chungnam Province of South Korea. Baekseokdong is located in Cheonan, Chungnam. 207 dwelling sites are concentrated around the area of $1.3km^2$ in the Baekseokdong. 177 dwelling sites are sparse and distributed over the area of $1.3km^2$ in the Yongdoocheon and Onyangcheon basins. Most of the Bronze Age dwelling sites in those areas located on the hill. The hills have similar geomorphological environments except for slight differences in geological faces. This study analyzes geomorphological environments of the high-density residential zone of the Bronze Age in the Yoodoocheon and the Onyangcheon basins, and then compares them with the results in Baekseokdong. Study results show that high-density residential zone consists mainly of specific micro-landforms such as the Crest slope, the Crest flat and the Upper side slope, and southeast-facing aspect. A lot of Gentle slope lands were distributed in terms of terrain slope but it is far from specific geomorphological environments. This is not weighted in specific value. Our results show that the geomorphological characteristic derived from this study is major considerations to develop dwelling sites in the Bronze Age. This can be useful to discover the possible dwelling sites over other Chungnam hill regions.

Manufacturing Digital Map Version 2.0 Increased Visual Information (시각적 정보력이 향상된 수치지도 Ver. 2.0제작)

  • Park Kyeong Sik;Lee Jae Kee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.23 no.3
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    • pp.221-231
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    • 2005
  • Though Digital Map Ver. 2.0 is adequate to GIS, the possibility to gain information from its external form and the ease of producing paper map had retrogressed. In this research, concerned with the problems, we plan to make Digital Map Ver. 2.0, which satisfies the conditions of GIS. It will have geometrical and logical data structure, and also possess informative ability as much as that of Ver. 1.0. For the study, the process to analyze the topographic code, color, code priority order, etc. of paper relief map, digital map Ver. 1.0, and digital map Ver. 2.0 was taken. For the topographical feature with diverse expression, we changed the portrayal of digital map Ver. 2.0 to make it fit the regulations of map portrayal. At the point of topographic code priority order, the rule is to arrange them in the same order as the real territory. However, we made a special code in the case of any change of the locational order. According to the property of this study, we observe the regulations of map portrayal, for the elements related to subjective sense, such as colors. And we give priority on the data construction when the portrayal of topographical feature and the schema of GIS database system are contradictory.

A Study on Spatial Structure Characteristics of Earthen Walled Fortresses (토성(土城)의 공간구조 특성 연구)

  • Lee, Sang-Seok;Jang, Mi-Ran
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.32 no.1
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    • pp.74-82
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    • 2014
  • The purposes of this study is to investigate spatial structure characteristics of earthen walled fortresses based on topography, which are locational and Plane morphology, Cross sections of earthworks. Target areas of this study are 37 earthen walled fortresses which are designated as cultural properties. This study is conducted with methodologies of literature review, field investigation, investigation on topography materials and relation analyses of topography&spatial structure. The results from study on spatial structure of earthen walled fortresses are as follows. First, Earthen walled fortresses on flat topography were adjacent to water systems like rivers or streams. Plane morphology showed regular shapes. The cross section morphology presented trapezoid the most with earthworks of which outer and inner walls were built. Second, More than 70% of earthen walled fortresses on hilly topography had water system within close range of approximately 1.5km. Plane morphology was mainly with more than 73% of irregular types. Cross sections of earthworks were of morphology with more than 86% of bordered type and another type leaning against existing topography like mountains. Third, 59% of earthen walled fortresses in mountain areas had water system within their close range, which indicated that they depended on external water system less than those with hilly topography. Plane morphology was mainly with more than 67% of irregular types. Cross sections of earthworks were of monoslope method with more than 94% of bordered type and another type leaning against mountains.

Study on Conversion Permission Standard considering the Topography and Ecological Location of the Mountain Areas (산지 지형 및 생태적 입지를 고려한 산지이용기준 개발에 관한 연구)

  • CHOI, Jung-Sun;KWAK, Doo-Ahn;KWON, Soon-Duck
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.4
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    • pp.59-71
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    • 2019
  • In Mountainous Districts Management Act of Korea Forest Service, slope and elevation criteria are operated to regulate the indiscriminate use of risky land parcels when forestland is converted to other land use types. However, there is a limitation in considering topographical variation with only such two indices in the land parcel. Therefore, in order to supplement insufficient criteria, the slope type standard was developed using Catena, and the ecological condition improved terrain standards. Firstly, the ratio of 'risky slope' in a target forestland parcel was defined to decrease the risk of disasters such as landslides. Secondly, the standard of the ecological location condition was proposed as ecological score by integrating age, diameter and soil depth classes in the target forestland parcels. Thereby, we could prepare reasonable standards that can reduce forestland disasters and ecological damages, as suggesting new topographical and ecological assessment methods for forestland use conversion.