• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.400-411
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• 2018

This study was a survey of the Wonju stream in Wonju city from May 2015 to September 2016. A total of three sites were selected from the upstream area Gwanseol-dong to the downstream area Hojeo-myeon. Physicochemical analysis, aquatic insect changes, cluster analysis, functional group analysis, rarefaction curve, and statistical analysis were compared between 2004 and 2016. A total of 19 species (38.78%) in 2004 and 22 species (36.67%) in 2016 were analyzed, with the largest number belonging to ephemeroptera. The individual ratio ranged from 27,759.2 (ind. $m^{-2}$, 84.30%) in 2004 to 4,573.2 (ind. $m^{-2}$, 41.64%) in 2016, with the highest number involving diptera. As a result of the community analysis, significant differences were detected in the indices of dominance, diversity, evenness, and richness in 2004 and 2016 (p<0.05). Burrowers of the habitat orientation groups showed the greatest variation with an average of -68.00% (${\pm}2.15$) and the collector-gatherers of the functional feeding groups showed the highest variation of -40.12% (${\pm}1.77$). The rarefaction curve analysis suggested that the species was the poorest in the midstream regions in 2004 and 2016. Physical factors and water quality showed a significant correlation with diversity index, evenness index, and the number of individuals. MDS analysis of the similarity of upstream and downstream regions was high in 2004, and low in 2016. The differences were attributed to physicochemical changes such as increase in flow velocity due to improvement of small dams and changes in bottom structure.

• Korean Journal of Heritage: History & Science
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• v.44 no.4
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• pp.112-129
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• 2011

This paper was written to understand, through the types and production techniques, how cooking vessels of Baekje Hanseong period had evolved, - the cooking vessels that were excavated from the historic sites of Baekje Hanseong Period such as Mongchontoseong and Pungnaptoseong of Seoul, the ancient tomb group of Seokchon-dong, and Misari historic site of Hanam. First, the results produced through the analysis of types of these cooking vessels are as followings: as for deep bowls, the maximum body diameter is found on the top of pottery, while as for an egg-shaped pottery, the maximum body diameter is found on the middle height of pottery. However, as for the rim diameter ratio to the neck diameter ratio of pottery, the said two typed potteries were shown to have smaller ones. In consideration of each historic site, as for deep bowls, the ancient tomb group of Seokchon-dong had potteries that had less volumes, were deeper, and had higher maximum body diameters. When it comes to an egg-shaped pottery, Pungnaptoseong had the potteries that were deeper than those of Misari historic site, and their potteries also had the maximum body diameter found on the middle height of pottery, and larger rim diameter ratio to the neck diameter of the pottery. The results produced though the analysis of the production techniques of these cooking vessels are as followings: in the case of deep bowls, as the width of a volume category gets larger, the pottery stamping with an anvil including patterns was more frequently used for pottery production. In this case, simultaneously braid patterns were frequently found on the outer sides of these potteries. In addition, it was found the basal walls of these potteries were thinnest in all typed potteries. This shows there occurred technique transitions according to the time flow. When it comes to an egg-shaped pottery as well, the pottery produced by using an anvil had the thinnest basal wall and its rim diameter ratio to its neck diameter ratio was smaller. Also around the mouth of this pottery, traces were found on its front, the traces formed by the strong rotating power. It is determined these two typed potteries were all produced by using an anvil to have thinner walls. Then, how these potteries were used? In the case of deep bowls, liquid food was put on a hearth or ground to be cooked whereas in the case of an egg-shaped pottery, the pottery was put on a puttumak(kitchen stove) mainly for boiling water. The deep bowls and egg-shaped potteries excavated from the center areas of Baekje Hanseong Period were not clearly determined about when their pastes or firing times were, but as for their production techniques, it was possible to check how they had developed. Moreover, it was determined that in the changing aspects of their production techniques, temporalite is also reflected.

• Journal of Korean Society of Forest Science
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• v.108 no.1
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• pp.40-49
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• 2019

Coarse woody debris (CWD), which is a component of the forest ecosystem, plays a major role in forest energy flow and nutrient cycling. In particular, CWD isolates carbon for a long time and is important in terms of slowing the rate of carbon released from the forest to the atmosphere. Therefore, this study measured the physiochemical characteristics and respiration rate ($R_{CWD}$) of CWD for Larix kaempferi and Pinus rigida in temperate forests in central Korea. In summer 2018, CWD samples from decay class (DC) I to IV were collected in the 14 forest stands. $R_{CWD}$ and physiochemical characteristics were measured using a closed chamber with a portable carbon dioxide sensor in the laboratory. In both species, as CWD decomposition progressed, the density ($D_{CWD}$) of the CWD decreased while the water content ($WC_{CWD}$) increased. Furthermore, the carbon concentrations did not significantly differ by DC, whereas the nitrogen concentration significantly increased and the C/N ratio decreased. The respiration rate of L. kaempferi CWD increased significantly up to DC IV, but for P. rigida it increased to DC II and then unchanged for DC II-IV. Accordingly, except for carbon concentration, all the measured characteristics showed a significant correlation with $R_{CWD}$. Multiple linear regression showed that $WC_{CWD}$ was the most influential factor on $R_{CWD}$. $WC_{CWD}$ affects $R_{CWD}$ by increasing microbial activity and is closely related to complex environmental factors such as temperature and light conditions. Therefore, it is necessary to study their correlation and estimate the time-series pattern of CWD moisture.

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.316-335
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• 2021

This study reviewed the change of theory of ecological niche(concepts and definitions) over time to provide a theoretical basis for habitat-related studies of animals and plants. Accordingly, it analyzed and summarized the major discussion trends of ecological niche worldwide in each period from the 1900s to the present. Countries advanced in ecological studies, such as the EU and the USA, have conducted theoretical and empirical studies on the ecological niche since the early 1990s. The concept of the ecological niche was introduced in the early 1900s, developed in the mid-1900s, and advanced from the mid-1900s to the late 1900s. Since the 2000s, the advanced concept has diversified with new developments in technologies and research methods. The factors suggested by theoretical and empirical studies in defining the ecological niche of a species include 1) population dynamics of the target species, 2) all biotic conditions to sustain a population (food relationship and material flow in the food chain), 3) all non-biotic conditions to sustain a population (physical environmental conditions), 4) all direct and indirect interactions between these environmental factors, and 5) response and adaptation mechanisms that include the migratory ability of the target species or genetic diversity and adaptability to change. Unlike such international advancement, there have not been sufficient theoretical, philosophical, and empirical studies of ecological niche in Korea. The concepts and definitions by Greennell, Elton, and Hutchinson were selectively and partially borrowed for empirical studies without full description. Considering that the theory of ecological niche becomes the foundation for habitat-based species conservation and restoration, it is necessary to seek diversification and advancement of theoretical and empirical research and research methods and technological development. It will provide an important foundation for the academic advancement of ecology and for establishing and implementing policies to preserve and restore ecology and biodiversity effectively and successfully in Korea.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.667-675
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• 2020

An Alum-sludge based adsorbent (ASBA) was synthesized by the hydrothermal treatment of alum sludge obtained from settling basin in water treatment plant. ASBA was applied to remove fluoride and arsenic in artificially-contaminated aqueous solutions and mine drainage. The mineralogical crystal structure, composition, and specific surface area of ASBA were identified. The result revealed that ASBA has irregular pores and a specific surface area of 87.25 ㎡ g-1 on its surface, which is advantageous for quick and facile adsorption. The main mineral components of the adsorbent were found to be quartz(SiO2), montmorillonite((Al,Mg)2Si4O10(OH)2·4H2O) and albite(NaAlSi3O8). The effects of pH, reaction time, initial concentration, and temperature on removal of fluoride and arsenic were examined. The results of the experiments showed that, the adsorbed amount of fluoride and arsenic gradually decreased with increasing pH. Based on the results of kinetic and isotherm experiments, the maximum adsorption capacity of fluoride and arsenic were 7.6 and 5.6 mg g-1, respectively. Developed models of fluoride and arsenic were suitable for the Langmuir and Freundlich models. Moreover, As for fluoride and arsenic, the increase rate of adsorption concentration decreased after 8 and 12 hr, respectively, after the start of the reaction. Also, the thermodynamic data showed that the amount of fluoride and arsenic adsorbed onto ASBA increased with increasing temperature from 25℃ to 35℃, indicating that the adsorption was endothermic and non-spontaneous reaction. As a result of regeneration experiments, ASBA can be regenerated by 1N of NaOH. In the actual mine drainage experiment, it was found that it has relatively high removal rates of 77% and 69%. The experimental results show ASBA is effective as an adsorbent for removal fluoride and arsenic from mine drainage, which has a small flow rate and acid/neutral pH environment.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.483-493
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• 2011

Erosion control dams play a primary role in preventing or controlling natural disasters (landslide and debris flow etc.) and also conserve ecosystem in forested watersheds. This study examines structural characteristics of the dams such as the height of ecosystem control and the ecosystem permeability of the erosion control dams under standard drawings and the existing construction works. The objective of this study was to characterize the type classification of erosion control dams as ecosystem. Average permeability was highest on eco-piller dam (63.0%), followed in increasing order by wire rope (13.9%), silt dam (10.9%), multifunctional dam (7.2%), and gravity dam (0.4%). The height of ecosystem control was highest on gravity dam (3.2 m), followed in increasing order by multifunctional dam (1.7 m), wire rope dam (1.2 m), silt dam (0.6 m), and eco-piller dam (0.0 m). Criteria for defining the height of ecosystem control was indefinite. We grouped erosion control dams into three functional types (eco-connection, eco-semi connection, and eco-disconnection) by considering physical and structural characteristics such as the ecosystem permeability and the height of ecosystem control. The type of eco-connection (permeability > 20%) had connection areas from streambed to adjacent riparian areas, and these connection areas serve as ecosystem corridors for fauna and flora. Typical wildlife species includes mammals, reptiles, amphibians, and fishes. The type of eco-semi connection (5% < permeability < 20%) had < 2 m in the eco-barrier height from streambed, however, this type of dams partially serve as wildlife corridors and often provide fish ways. The type of eco-disconnection (permeability < 5%) had > 2 m in the eco-barrier height from streambed, thereby preventing wildlife movement.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.1
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• pp.105-120
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• 2011

A moat is a pond or waterway paved on the outside of a fortress that is one of the facilities to prevent enemy from approaching the fortress wall or classify it as the boundary space, moats had existed in Europe, Asia and the America from ancient times to medieval times. however it is has been disappeared in modem society. In addition, a moat is a great value in historical and cultural sense such as offering a variety of cultural activities and habitats for animals, but unfortunately there is little consideration of its restoration plan. This research is aimed to investigate historical and cultural meaning and significance of moats which had been existing from ancient times to medieval times in the Eastern and Western. For this purpose, this research analyzed concepts and functions in consideration with times and ideological backgrounds of moats in Korea, China, and Japan. Results were as follows: 1. Moats in Korea existed not only in the castle towns of Goguryeo but also in ancient castle towns of Baekje and Silla. Natural moats and artificial moats existed around castles that were built to prevent and disconnect accessibility of enemies In Goryeo Dynasty and Chosun Dynasty, moats were also used as a defensive function. 2. A moat was generally installed by digging in the ground deep and wide at regular intervals from the ramparts, A moat was installed not only around a castle but also in its interiors. Moats outside castles played an important role in stomping the ground hard besides enhancing its defensive power. In addition, water bodies around a facility often discouraged people's access and walls or fences segregated space physically, but a moat with its open space had an alert and defensive means while pertaining its visual characteristics. 3. The moat found at Nagan Eupseong rumor has it that a village officials' strength was extremely tough due to strong energy of the blue dragon[Dongcheon] in Pungsujiri aspects, so such worries could be eliminated by letting the stream of the blue dragon flow in the form of 'S'. 4. The rampart of the Forbidden City of China is 7.9 meters high, and 3,428 meters long in circumference. It was built with 15 layers of bricks which were tamped down after being mixed with glutinous rice and earth, so it is really solid. The moat of the Forbidden City is 52 meters in width and 6 meters in depth, which surrounds the rampart of the Forbidden City, possibly blocking off enemies' approach. 5. Japan moats functioned as waterways due to their location in cities, further, with the arrangement of leisure facilities nearby, such as boating, fishing from boats, and restaurants, it helped relieve city dwellers' stress and functions as a lively city space. 6. Korean moats are smaller in scale than those of the Forbidden City of China, and Edo, and Osaka castles in Japan, Moats were mostly installed to protect royal palaces or castles in the Eastern Asia whereas moats were installed to protect kings, lords, or properties of wealthy people in the west.

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.634-649
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• 2020

Recently, stream longitudinal connectivity has been a topic of investigation due to the frequent disconnections and the impact of aquatic ecosystems caused by the construction of small and medium-sized weirs and various artificial structures (fishways) directly influencing the stream ecosystem health. In this study, the international and domestic research trends of the longitudinal connectivity in aquatic ecosystems were evaluated and the applicability of fish-based longitudinal connectivity models used in developed countries was analyzed. For these purposes, we analyzed the current status of research on longitudinal connectivity and structural problems, fish monitoring methodology, monitoring approaches, longitudinal disconnectivity of fish movement, and biodiversity. In addition, we analyzed the current status and some technical limitations of physical habitat suitability evaluation, ecology-based water flow, eco-hydrological modeling for fish habitat connectivity, and the s/w program development for agent-based model. Numerous references, data, and various reports were examined to identify worldwide longitudinal stream connectivity evaluation models in European and non-European countries. The international approaches to longitudinal connectivity evaluations were categorized into five phases including 1) an approach integrating fish community and artificial structure surveys (two types input variables), 2) field monitoring approaches, 3) a stream geomorphological approach, 4) an artificial structure-based DB analytical approach, and 5) other approaches. the overall evaluation of survey methodologies and applicability for longitudinal stream connectivity suggested that the ICE model (Information sur la Continuite Ecologique) and the ICF model (Index de Connectivitat Fluvial), widely used in European countries, were appropriate for the application of longitudinal connectivity evaluations in Korean streams.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.1
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• pp.40-53
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• 2021

Research vessels(R/Vs) used for ocean research move to the planned research area and perform ocean observations suitable for the research purpose. The five research vessels of the Korea Institute of Ocean Science & Technology(KIOST) are equipped with global positioning system(GPS), water depth, weather, sea surface layer temperature and salinity measurement equipment that can be observed at all times during cruise. An information platform is required to systematically manage and utilize the data produced through such continuous observation equipment. Therefore, the data flow was defined through a series of business analysis ranging from the research vessel operation plan to observation during the operation of the research vessel, data collection, data processing, data storage, display and service. After creating a functional design for each stage of the business process, KIOST Underway Meteorological & Oceanographic Information System(KUMOS), a Web-Geographic information system (Web-GIS) based information platform, was built. Since the data produced during the cruise of the R/Vs have characteristics of temporal and spatial variability, a quality management system was developed that considered these variabilities. For the systematic management and service of data, the KUMOS integrated Database(DB) was established, and functions such as R/V tracking, data display, search and provision were implemented. The dataset provided by KUMOS consists of cruise report, raw data, Quality Control(QC) flagged data, filtered data, cruise track line data, and data report for each cruise of the R/V. The business processing procedure and system of KUMOS for each function developed through this study are expected to serve as a benchmark for domestic ocean-related institutions and universities that have research vessels capable of continuous observations during cruise.

• Geophysics and Geophysical Exploration
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• v.24 no.4
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• pp.194-201
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• 2021

Induced polarization (IP) effect is known to be caused by electrochemical phenomena at interface between minerals and pore water. Spectral induced polarization (SIP) method is an electrical survey to localize subsurface IP anomalies while injecting alternating currents of multiple frequencies into the ground. This method was effectively applied to mineral exploration of various ore deposits. Titanomagnetite ores were being produced by a mining company located in Gonamsan area, Gwanin-myeon, Pocheon-si, Gyeonggi-do, South Korea. Because the ores contain more than 0.4 w% vanadium, the ore deposit is called as Gwanin vanadiferous titanomagnetite (VTM) deposit. The vanadium is the most important of materials in production of vanadium redox flow batteries, which can be appropriately used for large-scale energy storage system. Systematic mineral exploration was conducted to identify presence of hidden VTM orebodies and estimate their potential resources. In geophysical exploration, laboratory geophysical measurement of rock samples is helpful to generate reliable property models from field survey data. Therefore, we performed laboratory SIP data of the rocks from the Gwanin VTM deposit to understand SIP characteristics between ores and host rocks and then demonstrate the applicability of this method for the mineral exploration. Both phase and resistivity spectra of the ores sampled from underground outcrop and drilling cores were different of those of the host rocks consisting of monzodiorite and quartz monzodiorite. Because the phase and resistivity at frequencies below 100 Hz are mainly dependent on the SIP characteristics of the rocks, we calculated mean values of the ores and the host rocks. The average phase values at 0.1 Hz were ores: -369 mrad and host rocks: -39 mrad. The average resistivity values at 0.1 Hz were ores: 16 Ωm and host rocks: 2,623 Ωm. Because the SIP characteristics of the ores were different of those of the host rocks, we considered that the SIP survey is effective for the mineral exploration in vanadiferous titanomagnetite deposits and the SIP characteristics are useful for interpreting field survey data.