• Title/Summary/Keyword: drainage divide

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The Physical Region of China Divided by the Characteristics of Drainage Patterns. (하계망패턴의 특색으로 구분한 중국의 자연지역)

  • Hwang, Sang-Ill
    • Journal of the Korean association of regional geographers
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    • v.2 no.1
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    • pp.151-164
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    • 1996
  • The regional division by the characteristics of the drainage patterns is important to understand its physical environment comprehensively, because the drainage network develops in reflecting characteristics of geological, geographical and climatical features in the drainage basin keenly. This study is the attempt to divide physical region in China whose drainage pattern is diverse. Chinese drainage basin is mainly divided into the interior drainage basin and the peripheral drainage basin. The interior drainage basin is divided into (1)the deranged pattern and (2)the centripetal pattern. The peripheral drainage basin is divided into (1)the dendritic pattern, (2)the parallel pattern, (3)the radial pattern and (4)the anastomatic pattern. Drainage patterns of the interior drainage basin are formed by affecting geographical features and climatic conditions mainly. In the peripheral drainage basin, drainage patterns are formed by other factors: the parallel pattern is connected with geological structure lineament by tectonic movement, the radial pattern with changes of the river channel resulted from the Yellow River's overflow, the anastomotic pattern with human's activities. The distributional features of the physical region in China are as follows: The deranged pattern appears in Zangbai Plateau, the centripetal pattern does in arid basin of the northwest China. the parallel pattern does in Hengduan mountains affected strongly by tectonic movement between Yangtze paraplatform and Indian Plate, does in the upper stream of Yangtze River and Ganges River in the south of Qinghai-Xizang Plateau, the radial pattern in Huaihe Haihe River drainage basin appearing in the alluvial fan region of Yellow River's downstream and the anastomotic pattern does in the delta of Yangtze River, in the northern coastal plain of the Jiangsu-Province and in the delta of Zhujiang River. Except these areas in the peripheral drainage basin, the dendritic pattern is usually found in the other areas.

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Discussions on the Distribution and Genesis of Mountain Ranges in the Korean Peninsular (II) : The Proposal of 'Sanjulgi-Jido(Mountain Ridge Map)‘ (한국 산맥론(II): 한반도 '산줄기 지도'의 제안)

  • Park Soo Jin;SON ILL
    • Journal of the Korean Geographical Society
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    • v.40 no.3 s.108
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    • pp.253-273
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    • 2005
  • In recent years, there are strong social demands to characterize the spatial distribution of mountains in Korea. This study aims to develop a 'Sanjulgi-Jido(mountain ridge map)' that might be used not only to satisfy these social demands but also to effectively present the spatial distribution of mountains and drainage basins in the Korean Peninsular. The 'Sanjulgi-Jido' developed in this study is a map that presents the continuity of mountains based on the drainage divides that are delineated by a pre-defined drainage basin size and elevation. This study first validated the Bakdudaegan system through the analyses of a digital elevation model. The Bakdudaegan system has long been recognized as the Koreans traditional conceptual framework to characterize the spatial distribution of mountains. The analyses showed that the Bakdudaegan system has several problems to represent the mountain systems in Korea, which includes 1) the lack of the representativeness of drainage basins, 2) inaccuracy to depict the boundary of drainage basins, 3) the lack of representativeness of mountains, and 4) geo-polical issue that confines the spatial extent of mountain systems within the Korean Peninsular. In order to represent the mountains system in a more quantitative manner, we applied several terrain analysis techniques to understand the spatial distribution of mountains and drainage basins. Based on these analyses, we developed an hierarchical system to classify the continuity (If mountains, which are presented as the spatial distribution of drainage divides with a certain elevation. The first-order Sanjulgi is the drainage divides whose drainage basin are bigger than $5,000km^2$ and the point elevation is above 100m. The next order Sanjulgi is delineated as the size of drainage basin is successively divided by two. This kind of design is able to provide a logical framework to present the mountain systems at different details, depending on the purpose and scale of maps. We also provide several empirical functions to calculate various geomorphological indices for each order of Sanjulgi. The 'Sanjulgi Jido' is similar with the Bakdudaegan system, since it characterizes the continuity of mountains based on the spatial distribution of the drainage divide. It, however, has more scientific criteria to define the scale and continuity of mountains. It should be also noted that the 'Sanjulgi Jido' proposed has different logical and methodological background, compared with the mountain range map that explains the genesis of mountain systems in addition to the continuity of mountains.

Drainage Derangement and Revision by the Formation of Cheolwon-Pyeonggang Lava Plateau in Chugaryeong Rift Valley, Central Korea (추가령 열곡의 철원-평강 용암대지 형성에 따른 하계망 혼란과 재편성)

  • Lee Min-Boo;Lee Gwang-Ryul;Kim Nam-Shin
    • Journal of the Korean Geographical Society
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    • v.39 no.6 s.105
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    • pp.833-844
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    • 2004
  • In Chugaryeong rift valley, lava plateau formation by the fissure eruption had vanished original landforms and effected on drainage derangement and revision. 4 rivers including Namdae-cheon, Bukhan-gang, Imjin-gang and Hantan-gang watersheds have shared Cheolwon-Pyeonggang lava plateau, that is, ownerless watershed. Main agency of the dividing process are central-eruption volcanic peaks such as Orisan(453m) and 680 Peak. Especially, Orisan has played the role of divide point for 4 watersheds. In the lower-relief plateau zone, complex drainage system have caused continually river capture between neighboring watersheds. In more elevated range slope, river capture have proceeded to headward erosion. Hydrogeomorphologically, lava-filled valley has initiated decrease of the original size of flood plain, maybe, causing higher capability of inundation by heavy rains, and then more active dissection of lava plateau layer.

Geomorphic development of the Jeogchung·Chogye Basin and inner alluvial fan, Hapcheon, South Korea (합천 적중·초계분지와 분지 내 선상지 지형발달)

  • Hwang, Sangill;Yoon, Soon-Ock
    • Journal of the Korean association of regional geographers
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    • v.22 no.1
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    • pp.225-239
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    • 2016
  • The Jeogchung Chogye Basin shows perfect basin formation surrounded with divides, excluding outlet where Sannae River combining various small rivers escapes the basin. High mountains distribute at southwestern, southern and southeastern divides of the basin consisting of hornfels, while hilly mountains are found at northern divide consisting of sedimentary rock. Alluvial fans and flood plains occupy bottom of the basin. While extensive alluvial fans are found at the front of southern divide where rivers with large drainage areas rise, alluvial fans toward eastern and western divides become small due to low elevation of divides. Flood deposits by Hwang River are attributed to development for most of flood plains at northern part of the basin. The basin seems to be developed not by differential erosion or meteorite impact, but by bedrock weathering along lineament or fault lines by ground motion.

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A Geomorphic Surface Analysis Using Remote Sensing in DMZ of Chugaryeong Rift Valley, Central Korea (위성영상을 이용한 추가령열곡 DMZ 지역의 지형면 분석)

  • LEE, Min-Boo
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.1
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    • pp.1-14
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    • 2010
  • This paper deals with the classification and distribution of geomorphic surfaces and analysis on effects of geomorphic processes on the landforms in the inaccessable DMZ (Demilitarized Zone) to Wonsan Bay of East Sea coast of Chugaryeong Rift Valley, Central Korea. DEM (Digital Elevation Model) and Landsat images are used for the above anlaysis. The geomorphic surfaces are classified by TPI (Topographical Position Index) for the analysis of the convexity and concavity calculated using topographical elements such as elevation, steepness, and relief. In the Chugayreong Valley, 10 geomorphic surfaces are classified as steep valley, shallow valley, upland drainage, U-shaped valley, plain, open slope, upper slope, local ridge, midslope ridge, and high ridge. Zonal Statistics presents average characteristics of geomorphological processes of surfaces by the relationships between bedrock and relief, surface and relief, and between surface and NDVI. So, these analysis can help to understand geomorphological process such as dissection of lava plateau and watershed divide evolution.

The Effect on the Characteristics of Urban Storm Runoff due to the Space Allocation of Design Rainfall and the Partition of the Subbasin (도시유역에서의 강우 공간분포 및 소유역분할이 유출특성에 미치는 영향)

  • Lee, Jong-Tae;Lee, Sang-Tae
    • Journal of Korea Water Resources Association
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    • v.30 no.2
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    • pp.177-191
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    • 1997
  • The influences of the space allocation of design rainfall and partition of the subbasin on the characteristics of urban storm runoff was investigated for the 6 drainage basins by applying SWMM model. It show the deviation of -54.68∼18.77% in the peak discharge when we applied the composed JUFF quantiles to the two zones which are divided by upper and lower region of the basin. Then it is compared with the value for the case of using uniform rainfall distribution all over the drainage. Therefore, it would be helpful to decrease the flood risk when we adopt the space distribution of the design rainfall. The effects of the partitioning the drainage on the computing result shows various responses because of the surface characteristics of the each basin such as slope, imperviousness ratio, buy we can get closer result to the measured value as we make the subbasin detailed. If we use the concept of the skewness and area ratio when we determine the width of subbasin, we can improve the computed result even with fewer number of subbasins. We expect reasonable results which close into the measured results in the range of relative error, 25%, when we divide the basin into more than 3 subbasins and the total urban drainage area is less than 10$\textrm{km}^2$.

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Discussions on the Distribution and Genesis of Mountain Ranges in the Korean Peninsular (I) : The Identification Mountain Ranges using a DEM and Reconsideration of Current Issues on Mountain Range Maps (한국 산맥론(I) : DEM을 이용한 산맥의 확인과 현행 산맥도의 문제점 및 대안의 모색)

  • Park Soo Jin;SON ILL
    • Journal of the Korean Geographical Society
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    • v.40 no.1 s.106
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    • pp.126-152
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    • 2005
  • In recent years, there are some confusions related to the definition and existence of mountain ranges, which have been described in current geography text books. We contend that these confusions came from the lack of understanding on the geomorphological processes that form the mountain system in Korea. This research attempts to clarify the definition of mountain ranges and offer geological and geomorphological explanations about the formation of them. Based on the analyses of the social and cultural causes underlying the recent debates on the existence of mountain ranges, we tried to identify the relationships among the definition of mountain ranges, geological structure of Korea, and the forming processes of mountain ranges. The current and past mountain range maps were compared with geological structures, geological maps, surface curvature, and hill shade maps. The latter two maps were derived from a Digital Elevation Model of the Korean Peninsular. The results show that we are able to prove the existence of most mountain ranges, which provides a useful framework to understand the geological evolution of Korean peninsular and formation of mountainous landscape of Korea. In terms of their morphological continuity and genesis, however, we identified five different categories of mountain ranges: 1) Uplift mountain ranges(Hamkyeong Sanmaek, Nangrim Sanmaek, Taebaek Sanmaek), which were formed by the uplift processes of the Korean Peninsular during the Tertiary; 2) Falut mountain ranges(Macheonryeong Sanmaek, Sobaek Sanmaek, Buksubaek Sanmaek), whirh were directly related to the uplift processes of the Korean Peninsular during the Tertiary; 3) Trust mountain ranges(Jekyouryeong Sanmaek, Kwangju Sanmaek, Charyeong Sanmaek, Noryeong Sanmaek), which were formed by the intrusion of granite and consequent orogenic processes during the Mesozoic era; 4) Drainage divide type mountain ranges, which were formed by the erosion processes after the uplift of Korean Peninsular; 5) Cross-drainage basin type mountain ranges (Kangnam Sanmaek, Eunjin Sanmaek, Myelak sanmaek), which were also formed by the erosion processes, but the mountain ranges cross several drainage basins as connecting mountains laterally We believe that the current social confusions related to the existence of mountain ranges has partly been caused by the vague definition of mountain ranges and the diversity of the forming processes. In order to overcome theses confusions, it is necessary to characterize the types of them according the genesis, the purpose of usages and also the scale of maps which will explains the mountain systems. It is also necessary to provide appropriate educational materials to increase the general public's awareness and understanding of geomorphological processes.

The Study on the Dry Floor Tile Unit System used Resin Mat (수지매트를 이용한 바닥타일 건식공법 시스템에 관한 연구)

  • 김성식;임남기;정병훈;정재영;정상진
    • Journal of the Korea Institute of Building Construction
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    • v.1 no.2
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    • pp.185-190
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    • 2001
  • The purpose of this study is the development of practical Dry floor tile unit method that settle the defect of a wet method and designed for resin mat. With use of PE resin which is confirmed the basic property, it is developed that resin mat, joint-sealing compound with fixed form and space management to Dry floor tile unit method. The result of this study is below. 1) To acquire above the 4kgf/$\textrm{cm}^2$ - construction specification criterion, the bonding space that between resin mat and tile has to occupy the 50% of resin mat module space(10,000$\textrm{cm}^2$). 2) Criteria of bonding part plane is below. simpleness of metal form. productivity, uniform quality after injection molding cooling, easy cutting for remain space management, adhesive property, construction ability, transformation of a severed piece under pressure and so on. 3) To get the shape that could protect the interfacial breakdown, it is designed that resin mat and tile are unified after the bond input. 4) Adapted joint-sealing compound is the material of urethane kinds wedge form. Resin mat has the water passageway that could drain the water. 5) To manage the severed piece of tile, the resin mat is likely to divide the half and the quarter and the plastic drainage is developed in the severed piece.

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A Study on Chemical Compositions of Sediment and Surface Water in Nakdong River for Tracing Contaminants from Mining Activities (광해오염원 추적을 위한 낙동강 지역 퇴적물 및 하천수의 화학조성 연구)

  • Kim, Jiyun;Choi, Uikyu;Baek, Seung-Han;Choi, Hye-Bin;Lee, Jeonghoon
    • Journal of the Korean earth science society
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    • v.37 no.4
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    • pp.211-217
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    • 2016
  • There have been found mine tailings, wastes, and mining drainage scattered in the area of Nakdong River due to the improper maintenance of the abandoned mines. These contaminants can flow into rivers during the heavy rain periods in summer. Along the study area beginning Seokpo-myeon, Bonghwa-gun of Gyeongsangbuk-do untill Dosan-myeon, Andong-si, there are one hundred five mines including sixty metalliferous mines and forty-five nonmetal mines, which can adversely affect the adjacent rivers. To verify the contamination, we collected sediments, seepage water and surface water for a year both in rainy season and dry season. This study found that sediments, containing high concentrations of heavy metals caused by mining activities, are dispersed throughout the entire river basin (68 sample points with pollution index, based on the concentration of trace element, (PI) >10 among the total of 101 samples). The results of river water analysis indicated the increased concentrations of arsenic and cadmium at branches from Seungbu, Sambo, Okbang and Janggun mine, which concerns that the river water may be contaminated by mining drainage and tailing sediments. However, it is difficult to sort out the exact sources of contamination in sediments and waters only by using the chemical compositions. Thus the control of mining pollution is challenging. To prevent water from being contaminated by mining activities, we should be able to divide inflow rates from each origin of the mines. Therefore, there should be a continued study about how to trace the source of contaminants from mining activities by analyzing stable isotopes.