• Title/Summary/Keyword: landform development

Search Result 58, Processing Time 0.026 seconds

Mechanism of Wetland Formation according to Interaction of River Bed Fluctuation and Plant Success in the Hangang River Estuary (한강하구에서 하도변화와 식물천이의 상호작용에 따른 습지형성 기작)

  • Lee, Samhee;Youn, Sukzun
    • Journal of Wetlands Research
    • /
    • v.24 no.4
    • /
    • pp.320-330
    • /
    • 2022
  • The Hangang river estuary, which is a natural estuary without structures such as estuary barrage, is an ecological pathway connecting the sea and rivers. Accordingly, Hangang river estuary has various species, and there is very valuable. Sediment classification in Hangang river estuary is three-dimensionally and diversely is distributed. Sediment classification in Hangang river estuary is also sensitively changed according to various factors such as climate change and river development. It is typically cause to landform and to develop a compound cross section. In Janghang wetland, the plant success is remarkable according to the morphological change at river bed. The purpose of this study is to identify the mechanism of wetland formation based on the observation on-site. As a result of the observation, Janghang wetland where was artificially created, has been grown according to the river bed change based on the flow rate and the plant success. The viscous surface layer material(fine grains of wash rod properties), which is not the main material(sand) of the river bed, but sub-materials of river bed, jas been settled on the pioneer plants(bolboschoenus planiculmis, etc.). It is an important role in the growth of a compound cross section and a wetland. After the wetland developed to the compound cross section, it is observed that the pioneer plants are transferred to other plant species.

A study on Fault structures in the Chukaryong Rift Valley (의정부(議政府)-동두천(東豆川), 의정부(議政府)-포천간(抱川間)에 발달(發達)한 단층구조(斷層構造))

  • Kim, Joo-Hwan
    • Journal of the Speleological Society of Korea
    • /
    • no.75
    • /
    • pp.15-20
    • /
    • 2006
  • The purpose of this study is to clarify the fault structures in the Chukaryong Rift Valley. The Rift Valley has very significant meaning to interprete the development of Korean structural landforms. But till now the mechanism and processes of the formation of the Rift Valley are not clearly proved IMAGEM is very useful in this study. IMAGEM is developed by the Electromagnetic Instrument, Inc. and it covers $0.001{\sim}20,000Hz$. Form the fold survey data, it is certain that the faulted structures exist in the two points of the Rift Valley. But the Rift Valley is too long and braod to check the all evidences of the faulted structures.

Development of a CAD-based Utility for Topological Identification and Rasterized Mapping from Polygonal Vector Data (CAD 수단을 이용한 벡터형 공간자료의 위상 검출과 격자도면화를 위한 유틸리티 개발)

  • 조동범;임재현
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.27 no.4
    • /
    • pp.137-142
    • /
    • 1999
  • The purpose of this study is to develope a CAD-based tool for rasterization of polygonal vector map in AutoCAD. To identity the layer property of polygonal entity with user-defined coordinates as topology, algorithm in processing entity data of selection set that intersected with scan line was used, and the layers were extracted sequentially by sorted intersecting points in data-list. In addition to the functions for querying and modifying topology, two options for mapping were set up to construct plan projection type and to change meshes' properties in existing DTM data. In case of plan projection type, user-defined cell size of 3DFACE mesh is available for more detailed edge, and topological draping on landform can be executed in case of referring DTM data as an AutoCAD's drawing. The concept of algorithm was simple and clear, but some unexpectable errors were found in detecting intersected coordinates that were AutoCAD's error, not the utility's. Also, the routines to check these errors were included in algorithmic processing. Developed utility named MESHMAP was written in entity data control functions of AutoLISP language and dialog control language(DCL) for the purpose of user-oriented interactive usage. MESHMAP was proved to be more effective in data handling and time comparing with GRIDMAP module in LANDCADD which has similar function.

  • PDF

Change Detection of the Tonle Sap Floodplain, Cambodia, using ALOS PALSAR Data

  • Trung, Nguyen Van;Choi, Jung-Hyun;Won, Joong-Sun
    • Korean Journal of Remote Sensing
    • /
    • v.26 no.3
    • /
    • pp.287-295
    • /
    • 2010
  • Water level of the Tonle Sap is largely influenced by the Mekong River. During the wet season, the lacustrine landform and vegetated areas are covered with water. Change detection in this area provides information required for human activities and sustainable development around the Tonle Sap. In order to detect the changes in the Tonle Sap floodplain, fifteen ALOS-PALSAR L-band data acquired from January 2007 to January 2009 and examined in this study. Since L-band is able to penetrate into vegetation cover, it enables us to study the changes according to water level of floodplain developed in the rainforest. Four types of images were constructed and studied include 1) ratio images, 2) correlation coefficient images, 3) texture feature ratio images and 4) multi-color composite images. Change images (in each 46 day interval) extracted from the ratio images, coherence images and texture feature ratio images were formed for detecting land cover change. Two RGB images are also obtained by compositing three images acquired in the early, in the middle and at the end of the rainy season in 2007 and 2008. Combination of the methods results that the change images present the relationship between vegetation and water level, leaf fall forest as well as cultivation and harvest crop.

Distribution of Fault-related Landforms and Lineaments Along the Ulsan Fault Zone (울산단층대 주변의 단층 지형 및 선구조 분포)

  • Lee, Gwang-Ryul;Park, Chung-Sun;Shin, Jae-Ryul
    • Journal of The Geomorphological Association of Korea
    • /
    • v.25 no.3
    • /
    • pp.89-103
    • /
    • 2018
  • This study presents results of analysis on fault-related landforms and the Quaternary fluvial landforms, which are important evidences for active faulting by identifying surface deformation, around the Ulsan Fault Zone. In addition, this study suggests lineament map and inferred active fault-line map based on analyzing linearity and continuity of these landforms and by compiling location information of existing active faults. We convince that quantitative tectonic-geomorphological analysis are an effective method for active faults tracking, in particular, considering the conditions of relatively low seismicity and surface ruptured-events in the Korean Peninsula compared to plate boundary active areas. However, research on active fault in South Korea is just an infant stage since the 1990s and requires accumulation of research achievements on development and application of various fault analysis techniques, analysing and standardizing linear structures.

Research of landscape ecological field-trip learning program development for students at BiIn Bay, Seocheon in South Chung-chong coastal environment (비인만의 해안사구를 활용한 경관생태적 현장학습 프로그램 개발)

  • KANG, Tay-Gyoon
    • Journal of The Geomorphological Association of Korea
    • /
    • v.26 no.1
    • /
    • pp.121-131
    • /
    • 2019
  • The coast of BiIn Bay, Seocheon, is the potential site for the field-trip learning program. This article is written in the viewpoint of geographical and environmental education. In this study, it is tried to describe geomorphological landscapes of BiIn Bay Seocheon-gun relating with it's physiognomy, based on the Dasa-ri and Songrim-ri coastal sanddunes and the like. Although landforms like tidal flats and rock cliff constitute prominent landscape features in this area, other features such as beaches, coastal dunes, and coastal plains have various ramifications for human communities. Tidal flats, beaches and coastal dunes are formed by the combined actions of longshore current, tidal flows, waves and winds. To some extent, the erosion of sandy coast has been a global phenomenon. Anthropogenic impacts are involved in the transformation of landform. Most favorable field-trip course of BiIn Bay is from Songrim-ri through Dasa-ri and Shinhap-ri to Maryang-ri. This program about coastal landforms in BiIn Bay will contribute not only for educational meanings but also for satisfying the student' curiosity and interest. Also, this field-trip learning program will be suitable for over 4th grade elementary school students and middle school students.

Geomorphological significance and role of the sand bars of major river valleys in the South Korea - case study on the Nakdong river valleys - (한국 하천 모래톱의 지형학적 의미와 효능 - 낙동강 하곡을 사례로 -)

  • OH, Kyung-Seob;YANG, Jae-Hyuk;CHO, Heon
    • Journal of The Geomorphological Association of Korea
    • /
    • v.18 no.2
    • /
    • pp.1-14
    • /
    • 2011
  • Remarkable development of sand bars is an important characteristic of fluviatile landform of Korea. Their development owes, in one part, to the supply of abundant sandy materials to river valley floor, originated from the weathering of essentially granitic rocks, distributed almost all over the country. It owes, in other part, to river valley disposition presenting many angular sinuosity guided by fracture grid, impeding regular migration of sandy materials along valley floor. Besides, high amplitude of river discharge fluctuation of the country plays is proved to be favorable hydrological factor for the development of the sand bars. The sand bars play important roles in favor of river hydro-ecological environment. They mitigate the amplitude of discharge fluctuation regime. In flood spell, sand grains in the main channel migrate so as to broden wet section. At the spell of low water level, they newly accumulate as to impede rapid stream discharge. Especially high quantity of reserved water in porous space of sand bar is preciously available both for human livelihood and for ecological environment.

Regional Differential Development as an Alternative Regional Development Theory (대안적 지역발전론으로서 지역차이발전론)

  • Lee, Jae-Ha
    • Journal of the Korean Geographical Society
    • /
    • v.47 no.1
    • /
    • pp.140-157
    • /
    • 2012
  • Most of global citizens in the globalization era want to live peacefully in the symbiotic relationship among each region or locality with its identity. From this perspective, the new regionalist models of development such as new industrial districts, industrial clusters, regional innovation systems, and global city-regions isn't helpful to most of regions because they were developed to increase the global competitiveness of industrial region from a few advanced industrial areas. This study attempts to develop 'regional differential development' as an alternative regional development theory. This theory puts emphasis on the truth that the difference or differential industry between regions in the real world connotes two essential values of development like the symbiosis of global citizens and the regional identity. Regional differential development seeks the development of regional differential industry on the basis of geographical elements with differential advantage, and hence it reviews significantly geographical elements including location, natural environment(landform, soil, climate, etc.), natural resources, population, transportation, culture, and landscape which appear substantially differently among regions. And to realize regional differential development successfully, it is crucial that actors(government, company, related institutions, and regional residents) actively participate and play each complementary role in the relationship of cooperation and conflict. Further study needs to secure the universal validity of this theory through many empirical studies.

  • PDF

Taebaek Mountainous Region as a Natural Unit (자연 지역으로서의 태백 산지)

  • Kee, Keun-Doh
    • Journal of the Korean association of regional geographers
    • /
    • v.8 no.4
    • /
    • pp.468-479
    • /
    • 2002
  • This study attempts to characterize Taebaek mountainous region as a natural unit, relating to morphoclimatic milieu and landform development patterns of the mountains of each lithologic type. In the case of granitic mountains of Nothern parts of this region, the slopes presents more or less steep or irregular profile because of abundant microforms of exposed bedrocks and blocks. The development of such landscape is essentially due to differential weathering, associated with difference of joint density. In the case of gneissic mountains, the slopes are well regularized straight steep ones, due not only to generalized superficial weathering but also to massmovement of weathered materials. In the Middle parts of this region, especially in Taegwallyong area, with frequent alternations both of freezing-thawing and of snow accumulation-melting, the roles played by cryo-nival processes proved to be important in weathering of granite as well as in morpho-pedogenesis. In this area, weathered mantle, developed by cryogenic activity under humid condition of nival environment, covered almost all over the slopes. Although Southern parts of this region consist of limestone, on the mountainous volume, distribution of Karst forms are limited while predominate none karst forms such as cockpit type peaks, V-shaped type valleys dissecting steep slopes covered with thin deposits in thickness containing rock debris.

  • PDF

Geomorphic Development of Gnamma at the Summit Area of Mt. Geum, Sangju-ri, Namhae-gun, Gyeongsangnam-do (남해군 금산 정상부의 나마(Gnamma) 지형발달)

  • Hwang, Sang-Ill;Park, Hyo-Jung;Park, Kyung-Geun;Yoon, Soon-Ock
    • Journal of the Korean Geographical Society
    • /
    • v.46 no.2
    • /
    • pp.134-151
    • /
    • 2011
  • The types of gnamma at the summit area of Mt. Geum, Sangju-ri, Namhae-gun, Gyeongsangnam-do are classified and geomorphic developments are investigated. The rocks facing the coast show high distributional density of gnamma due to the salt supply from the coast. The water content rate of gnamma distributed in flat rocks at the summit is highest in the bottom area and lowest in the outside area. Moreover, the quartz grains are fallen due to the weathering of feldspar in the crystalline rocks such as granites and the gnamma are merged and expanded as they develop. The average weathering rate of gnamma is 0.04mm/y and it slowed with time. The results on rate indicate that the gnamma are formed and developed at the present rather than the fossil landform or by subsurface weathering.