• 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.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.90-104
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• 2001

This study is aimed to analyze and to evaluate the revegetation and soil conservation technology in desertification-affected sandy land, resulting from the project of "Studies on the desertification combating and sand industry development". Main native plants for combating desertification : The general characteristics of vegetation distribution in desertified regions are partially concentrated vegetation distribution types including the a) desert plants in low zone of desert or sanddune of depressed basin, b) salt-resistant plants around saline lakes, c) grouped vegetation with Poplar and Chinese Tamarix of freshwater-lakes, saline-lakes and river-banks, d) gobi vegetation of gravel desert and e) grassland and oasis-woods around the alluvial fan of rivers, etc. Generally, Tamarix ehinensis Lour., Haloxylon ammodendron Bunge., Calligonum spp., Populus euphratica Oliver., Elaeagnus angustifolia L., Ulmus pumila L., Salix spp., Hedysarum spp., Caragana spp., Xanthoceras sorbifolia Bunge., Nitraria tangutorum Bobr., Lespedeza bicolor, Alhagi sparsifolia Shap., Capparis spinosa L., Artemisia arenaria DC., etc. are widely distributed in desertified regions. It is necessary for conducting research in the native plants in desertified regions. Analysis of intensive revegetation technology system for combating desertification : In the wind erosion region, the experimental research projects of rational farming systems (regional planning, shelterbelts system, protection system of oasis, establishment of irrigation-channel networks and management technology of enormous farmlands, etc.), rational utilization technology of plant resources (fuelwood, medicinal plants, grazing and grassland management, etc.), utilization technology of water resources (management and planning of watershed, construction of channel and technology of water saving and irrigation, etc.), establishment of sheltetbelts, control of population increase and increased production technology of agricultural forest, fuelwood and feed, etc. are preponderantly being promoted. And in water erosion region, the experimental research projects of development of rational utilization technology of land and vegetation, engineering technology and protection technology of crops, etc. are being promoted in priority. And also, the experimental researches on the methods of utilization of water (irrigation, drainage, washing and rice cultivation, etc.), agricultural methods (reclamation of land, agronomy, fertilization, seeding, crop rotation, mixed-cultivation and soil dressing works, etc.) and biological methods (cultivation of salt-resistant crops and green manure and tree plantation, etc.) for improvement of saline soil and alkaline soil in desertified-lands are actively being promoted. And the international cooperations on the revegetation technology development projects of desertified-lands are sincerely being required.

• Economic and Environmental Geology
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• v.44 no.5
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• pp.399-412
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• 2011

A DEM (digital elevation model) is produced using a digital topographic map and is now a commonly used tool in geologic surveys. This study aimed to clarify the relationship between knickpoints and faults in the Namdae stream by analyzing a DEM of the area. The Namdae drainage basin was divided into three subbasins (S1, S2 and S3) and their knickpoints developed for the middle to mid-upper regions were extracted from the DEM. The relative steepness Ks and concavity depending on the incision rate was higher in S1 than in S2 and S3 regions. We assumed that the incision rate caused by active erosion resulted from several faults crossing the basins rather than differences in rock types. There are 77 knickpoints in the Namdae drainage area, including the low-ranking branch, and 24 of thses are on the main river system (S1, S2, S3). Of these 77 knickpoints, 27 (38%) are matched by faults, and from the three basins, 13 (54%) correspond with faults, indicating that the knickpoints are connected closely with the faults. For example the average Ks (relative steepness), was 38.8, but in the overlapping area of the Samdang and Doocheon faults the Ks value was 42.99~43.39. We suggest that the faults resulted in geomorphic deformation such as the high-Ksn knickpoints. There was little evdence of relationship between the knickpoints and rock boundaries, with 54% of the knickpoints distributed on the S1, S2, and S3 subbasins. We concluded that the drainage basin knickpoints are the result of fault movement and are a type of geomorphologic deformation that could be useful for surveying Quaternary faults or fault extension.

• Journal of the Korean Geographical Society
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• v.42 no.3 s.120
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• pp.368-387
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• 2007

In order to explain geomorphological characteristics of the Korean Peninsula, it is necessary to understand the spatial distribution of tectonic movements and its causes. Even though geomorphological elements which might have been formed by tectonic movements(e.g. tilted overall landform, erosion surface, river terrace, marine terraces, etc.) have long been considered as main geomorphological research topics in Korea, the knowledge on the spatial distribution of tectonic movement is still limited. This research aims to identify the spatial distributions of tectonic movement via sequential analyses of Digital Elevation Model(DEM). This paper first developed a set of terrain analysis techniques derived from theoretical interrelationships between tectonic uplifts and landsurface denudation processes. The terrain analyses used in this research assume that elevations along major drainage basin divides might preserve original landsurfaces(psuedo-landsuface) that were formed by tectonic movement with relatively little influence by denudation processes. Psuedo-landsurfaces derived from a DEM show clear spatial distribution patterns with distinct directional alignments. Lines connecting psuedo-landsufaces in a certain direction are defined as psuedo-landsurface axes, which are again categorized into two groups: the first is uplift psuedo-landsurface axes that indicate the axis of landmass uplift; and the second is denudational psuedo-landsurface axes that cross step-shaped pusedo-landsurfaces formed via surface denudation. In total, 13 axes of pusedo-landsurface are identified in the Korean Peninsula, which show distinct direction, length, and relative uplift rate. Judging from the distribution of psudo-landsurfaces and their axes, it is concluded that the Korean Peninsula ran be divided into four tectonic regions, which are named as the Northern Tectonic Region, Center Tectonic Region, Southern Tectonic Region, and East Sea Tectonic Region, respectively. The Northern Tectonic Region had experienced a regional uplift centered at the Kaema plateau, and the rate of uplift gradually decreased toward southern, western and eastern directions. The Center Tectonic Region shows an arch-shaped uplift. Its uplift rate is the highest along the East Sea and the rate decreases towards the Yellow sea. The Southern Tectonic Region shows an asymmetric uplift centered a line connecting Dukyu and Jiri Mountains in the middle of the region. The eastern side of the Southern Regions shows higher uplift rate than that of the western side. The East Sea Tectonic Region includes south-eastern coastal area of the peninsula and Gilju-Myeongchun Jigudae, which shows relatively recent tectonic movements in Korea. Since this research visualizes the spatial heterogeneity of long-term tenonic movement in the Korean peninsula, this would provide valuable basic information on long-term and regional differences of geomorphological evolutionary processes and regional geomorphological differences of the Korean Peninsula.

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.512-527
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• 2012

Jangdo Island (area $1.54km^2$) located in the western end of Dadohae Haesang National Park has been recognized as an prominent ecoregion possessing high moor and national biodiversity hotspot. In terms of the Z$\ddot{u}$rich-Montpellier School's phytosociology, we investigate the diversity of plant communities on the island and reevaluate the Jangdo wetland designated as Ramsar site. Ten physiognomic types of the Jangdo's vegetation were classified into 22 syntaxa (3 associations, 15 communities and 4 subcommunities). Jangdo wetland was actually denominated as 'eutrophic wetland' by Pharagmitetea and Orizetea rather than 'high moor'. Nevertheless, existence value of the Jangdo wetland is evaluated very high as a stepping stone for migratory birds and even plant dispersions. A new site of the northernmost distribution of Arachniodo-Castanopsietum sieboldii, which is a kind of cold-resistant phytocoenosis among the Camellietea japonicae of the warm-temperate broad-leaved forests, was described. Hosta yingeri-Carpinus turczaninovii var. coreana community and Carex wahuensis var. robusta-Juniperus chinensis var. procumbens community were described specifically as an endemic and an edaphic vegetation type, respectively. The unique Jangdo's vegetation reflects regional environmental conditions such as much higher frequency of frost-free days and the highest number of annual average foggy days in Korea and a well-developed aquifer in the depressed basin formed by differential erosion. We identified that human interventions (pasture, logging, forest fire, cultivation, etc.) has been involved intensively on every vegetation types, even though a rugged and inaccessible topography of the island. Particularly the Jangdo wetland has been recently threatened by fundamental distortion on hydrological system. We request an immediate establishment of the conservation prescription manual.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.33-41
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• 2001

Enormous volumes of mining wastes from the abandoned and closed mines are disposed without a proper treatment in the upper Okdong River basin at Southeastern part of Kangwon Province. Erosion of these wastes contaminates soil, surface water, and sediments with heavy metals. Objectives of this research were to fractionate heavy metals in the mine tailing stored in the Sangdong Tungsten tailing dams and to assess the potential pollution index of each metal fraction. Tailing samples were collected from tailing dams at different depth and analyzed for physical and chemical properties. pH of tailings ranged from 7.3 to 7.9. Contents of total N and organic matter were in the ranges of 3.2~5.5%, and 1.3~9.1%, respectively. Heavy metals in the tailings were higher in the newly constructed tailing dam than those in the old dam. Total concentrations of metals in the tailings were in the orders of Zn > Cu > Pb > Ni > Cd, exceeded the corrective action level of the Soil Environment Conservation Law and higher than the natural abundance levels reported from uncontaminated soils. Relative distribution of heavy metal fractions was residual > organic > reducible > carbonate > adsorbed, reversing the degree of metal bioavailability. Mobile fractions of metals were relatively small compared to the total concentrations. Distribution of metals in the tailing dam profiles was metal specific. Concentrations of Cu at the surface of tailing dams were higher than those at the bottom. Pollution index (PI) values of each fraction of metals were ranged from 4.27 to 8.51 based on total concentrations. PI values of mobile fractions were lower than those of immobile fractions. Results on metal fractions and PI values of the tailing samples indicate that tailing samples were contaminated with heavy metals and had potential to cause a detrimental effects on soil and water environment in the lower part of the stream. A prompt countermeasure to prevent surface of tailings in the dams from water and wind erosions is urgently needed.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.12-24
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• 2020

The purpose of this study is to analyze the influence of the water system on the location, spatial structure, and construction method of Hongju-eupseong, centering on Hongjumok-eupchi. During the Joseon Dynasty, the water system in Hongjumok-eupchi is composed of artificially constructed Seong-an Runnel and ponds based on a branch-shaped natural waterways flowing from south to north and west to east. Compiling the results of various literature records, excavations and analysis of map data, it can be seen that the water system has an important influence on the construction of Hongju-seong. Firstly, Hongju-seong from the Goryeo Dynasty to the late Joseon Dynasty is located using a circular shape of topographical structure and a small erosion basin formed on the inner side of the Hongseongcheon and Wolgyecheon streams without significant change in location. In particular, Wolgyecheon and Hongseongcheon are natural moats, which are harmonized with Sohyangcheon and riverside topographical structures, affecting the location and construction method of Hongju-seong, water related facilities, and the spatial structure of eupseong. It is understood that location characteristic of Hongju-seong reflects the urban location structure harmonized with waterways in ancient China and Korea. Secondly in harmony with the water system and topographic structure of Hongju-seong, it is an important factor in deciding the land use of the town, the arrangement of the town hall facilities and inducing various non-subsidiary measures such as the establishment of embankment forest with a secret function and the closure of the south gate. In addition, artificial drainage facilities such as Seongan runnel and ponds are being actively introduced from early on to protect the walls or towns from flooding of Wolgyecheon. Especially there were typical methods for protecting the walls from water damage such as the Joseon Dynasty stone castle structure that was integrated with saturn(soil wall) in the Goryeo Dynasty, retreating wall in the northern gate area in the late Joseon Dynasty, and the method of constructing wall using korean tile and stone floors between reinforced soil layers in the western and northern wall.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.1
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• pp.2206-2217
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• 1971

Spillway and discharge channel of reservoirs require the Control of Large volume of water under high pressure. The energies at the downstream end of spillway or discharge channel are tremendous. Therefore, Some means of expending the energy of the high-velocity flow is required to prevent scour of the riverbed, minimize erosion, and prevent undermining structures or dam it self. This may be accomplished by Constructing an energy dissipator at the downstream end of spillway or discharge channel disigned to dissipated the excessive energy and establish safe flow Condition in the outlet channel. There are many types of energy dissipators, stilling basins are the most familar energy dissipator. In the stilling basin, most energies are dissipated by hydraulic jump. stilling basins have some length to cover hydraulic jump length. So stilling basins require much concrete works and high construction cost. Flip bucket type energy dissipators require less construction cost. If the streambed is composed of firm rock and it is certain that the scour will not progress upstream to the extent that the safety of the structure might be endangered, flip backet type energy dissipators are the most recommendable one. Following items are tested and studied with bucket radius, $R=7h_2$,(medium of $4h_2{\geqq}R{\geqq}10h_2$). 1. Allowable upstream channel slop of bucket. 2. Adequate bucket lip angle for good performance of flip bucket. Also followings are reviwed. 1. Scour by jet flow. 2. Negative pressure distribution and air movement below nappe flow. From the test and study, following results were obtained. 1. Upstream channel slope of bucket (S=H/L) should be 0.25<H/L<0.75 for good performance of flip bucket. 2. Adequated lip angle $30^{\circ}{\sim}40^{\circ}$ are more reliable than $20^{\circ}{\sim}30^{\circ}$ for the safety of structures.

• Water for future
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• v.9 no.1
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• pp.38-42
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• 1976

Because of differences in thoughts and ideology, our country, Korea has been deprived of national unity for some thirty years of time and tide. To achieve peaceful unification, the cultivation of national strength is of paramount importance. This national strength is also essential if Korea is to take rightful place in the international societies and to have the confidence of these societies. However, national strength can never be achieved in a short time. The fundamental elements in economic development that are directly conducive to the cultivation of national strength can be said to lie in -a stable political system, -exertion of powerful leadership, -cultivation of a spirit of diligence, self-help and cooperation, -modernization of human brain power, and -establishment of a scientific and well planned economic policy and strong enforcement of this policy. Our country, Korea, has attained brilliant economic development in the past 15 years under the strong leadership of president Park Chung Hee. However, there are still many problems to be solved. A few of them are: -housing and home problems, -increasing demand for employment, -increasing demand for staple food and -the need to improve international balance of payment. Solution of the above mentioned problems requires step by step scientific development of each sector and region of our contry. As a spearhead project in regional development, the Saemaul Campaign or new village movement can be cited. The campaign is now spreading throughout the country like a grass fire. However, such campaigns need considerable encouragement and support and the means for the desired development must be provided if the regional and sectoral development program is to sucdceed. The construction of large multipurpose dams in major river basin plays significant role in all aspects of national, regional and sectoral development. It ensures that the water resource, for which there is no substitute, is retained and utilized for irrigation of agricultural areas, production of power for industry, provision of water for domestic and industrial uses and control of river water. Water is the very essence of life and we must conserve and utilize what we have for the betterment of our peoples and their heir. The regional and social impact of construction of a large dam is enormous. It is intended to, and does, dras tically improve the "without-project" socio-economic conditions. A good example of this is the Soyanggang multipurpose dam. This project will significantly contribute to our national strength by utilizing the stored water for the benefit of human life and relief of flood and drought damages. Annual average precipitation in Korea is 1160mm, a comparatively abundant amount. The catchment areas of the Han River, Keum River, and Youngsan River are $62,755\textrm{km}^2$, accounting for 64% of the national total. Approximately 62% of the national population inhabits in this area, and 67% of the national gross product comes from the area. The annual population growth rate of the country is currently estimated at 1.7%, and every year the population growth in urban area increases at a rising rate. The population of Seoul, Pusan, and Taegu, the three major cities in Korea, is equal to one third of our national total. According to the census conducted on October 1, 1975, the population in the urban areas has increased by 384,000, whereas that in rural areas has decreased by 59,000,000 in the past five years. The composition of population between urban and rural areas varied from 41%~59% in 1959 to 48%~52% in 1975. To mitigate this treand towards concentration of population in urban areas, employment opportunities must be provided in regional and rural areas. However, heavy and chemical industries, which mitigate production and employment problems at the same time, must have abundant water and energy. Also increase in staple food production cannot be attained without water. At this point in time, when water demand is rapidly growing, it is essential for the country to provide as much a reservoir capacity as possible to capture the monsoon rainfall, which concentarated in the rainy seaon from June to Septesmber, and conserve the water for year round use. The floods, which at one time we called "the devil" have now become a source of immense benefit to Korea. Let me explain the topographic condition in Korea. In northern and eastern areas we have high mountains and rugged country. Our rivers originate in these mountains and flow in a general southerly or westerly direction throught ancient plains. These plains were formed by progressive deposition of sediments from the mountains and provide our country with large areas of fertile land, emminently suited to settlement and irrigated agricultural development. It is, therefore, quite natural that these areas should become the polar point for our regional development program. Hower, we are fortunate in that we have an additional area or areas, which can be used for agricultural production and settlement of our peoples, particularly those peoples who may be displaced by the formation of our reservoirs. I am speaking of the tidelands along the western and southern coasts. The other day the Ministry of Agriculture and Fishery informed the public of a tideland reclamation of which 400,000 hectares will be used for growing rice as part of our national food self-sufficiency programme. Now, again, we arrive at the need for water, as without it we cannot realize this ambitious programme. And again we need those dams to provide it. As I mentioned before, dams not only provide us with essential water for agriculture, domestic and industrial use, but provide us with electrical energy, as it is generally extremely economical to use the water being release for the former purposes to drive turbines and generators. At the present time we have 13 hydro-electric power plants with an installed capacity of 711,000 kilowatts equal to 16% of our national total. There are about 110 potential dams ites in the country, which could yield about 2,300,000 kilowatts of hydro-electric power. There are about 54 sites suitable for pumped storage which could produce a further 38,600,000 kilowatts of power. All available if we carefully develop our water resources. To summarize, water resource development is essential to the regional development program and the welfare of our people, it must proceed hand-in-hand with other aspects of regional development such as land impovement, high way extension, development of our forests, erosion control, and develop ment of heavy and chemical industries. Through the successful implementation of such an integrated regional development program, we can look forward to a period of national strength, and due recognition of our country by the worlds societies.