• Economic and Environmental Geology
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• v.55 no.5
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• pp.477-495
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• 2022

This study examined the sustainability of CO₂-rich water by analyzing the water level and water quality change pattern with the amount of its use in Angseong area, Chungju. The origin and supply of CO₂ component were discussed in consideration of ⁸⁷Sr/⁸⁶Sr ratio, occurrence of CO₂-rich fluid inclusions in nearby W-Mo deposits and other surrounding geological characteristics. According to the data from 1986 to 2017, the depth of the water level of CO₂-rich water was significantly lowered in the late period (2009-2015) than in the early period (1986-1992) of the development of hot spa wells, and the optimal yields for pumping tests also showed a tendency to gradual decrease. Concentrations of CO₂ component also decreased continuously in the later stages compared to the early stages of development, but it has been stable since 2012. It is inferred that the geological environment related to forming W-Mo quartz vein deposits (0.5×1.5×several km) around the study area are largely involved in the origin and supply of CO₂ component, and the supply of CO₂ component is not infinitely supplied from deep current magma activity. Rather, since it is finitely supplied from a restricted subsurface region formed in the past geological period, it is necessary to efficiently control its use in order to maintain the sustainability of CO₂-rich water in the study area.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.52-60
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• 2016

This study investigates and analyzes the total amount of energy consumption and $CO_2$ emission during the material manufacturing, transportation, construction, operation, and disposal phases of eight elementary school buildings in South Korea. Toward this ends, the hybrid LCA model is proposed. The life cycle energy consumption and $CO_2$ emission of eight case buildings are assessed using the hybrid LCA model with an assumption that the operation period is 40 years. As a result, the embodied(sum of the energy consumption in the material manufacturing, transportation and construction phases), operational and disposal energy were 2,279, 11,182, $228Mcal/m^2$, respectively, on average. The average embodied, operational, and disposal $CO_2$ emission were 604, 2,708, 60 kg-$CO_2/m^2$, respectively, on average. This result indicates that about 17% of life cycle energy (or $CO_2$ emission) is consumed in the material manufacturing, transportation and construction phases. Thus, it is necessary to consider the embodied energy and $CO_2$ emission to reduce the life cycle energy and $CO_2$ emission of school buildings. In addition, while the insulation standard of building have been provided based on the climate zone, energy consumption in operation phase still varied depending on the regions in this study. Thus, the insulation standard of building needs to be improved through considering the climate of regions in detail.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.2
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• pp.102-107
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• 2015

This study was conducted to classify agro-climatic zones in Northeast district of China. For agro-climatic zoning, monthly mean temperature and precipitation data from Global Modeling and Assimilation Office (GMAO) of National Aeronautics and Space Administration (NASA, USA) between 1979 and 2010 (http://disc.sci.gsfc.nasa.gov/) were collected. Altitude and vegetation fraction of East Asia from Weather Research and Forecasting (WRF) were also used to classify them. The criteria of agro-climatic classification were altitude (200 m, between 200-800 m, 800 m), vegetation fraction (60%), annual mean temperature ($0^{\circ}C$), temperature in the hottest month ($22^{\circ}C$), and annual precipitation (700 mm). In Northeast district of China, mean annual temperature, annual precipitation, and solar radiation were $3.4^{\circ}C$, 613.2 mm, and $4,414.2MJ/m^2$ between 2009 and 2013, respectively. Twenty-two agro-climatic zones identified in Northeast district of China by metrics classification method, from which the map of agro-climatic zones for Northeast district of China was derived. The results could be useful as information for estimating agro-meteorological characteristics and predicting crop development and crop yield of Northeast district of China as well as those of North Korea.

• Ocean and Polar Research
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• v.36 no.4
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• pp.407-421
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• 2014

The benthic environmental impact experiment addresses environmental impacts at a specific site related to deep-sea mineral resource development. We have acquired several tens of multi- or box core samples at 31 sites within the Benthic environmental Impact Site (BIS) since 2010, aiming to examine the basic properties of surficial deep-sea sediment as a potential source for deep-water plumes. In this study, we present the geochemical properties such as major elements, rare earth elements (REEs), and heavy metal contents at the BIS. Such proxies vary distinctly according to the Facies association. The lithology of all core sediments in the BIS corresponds to both Association Ib and Association IIIb. The vertical profiles of some major elements ($SiO_2$, $Fe_2O_3$, CaO, $P_2O_5$, MgO, MnO) show noticeable differences between Association Ib and IIIb, while others ($Al_2O_3$, $TiO_2$, $Na_2O$, and $K_2O$) do not vary between Association Ib and IIIb. REEs are also distinctly different for Associations Ib and IIIb; in Association Ib, REY and HREE/LREE are uniform through the sediment section, while they increase downward in Association IIIb like the major elements; below a depth of 8 cm, REY is over 500 ppm. The metal enrichment factor (EF) evaluates the anthropogenic influences of some metals (Cu, Ni, Pb, Zn, and Cd) in marine sediments. In both Associations, the EF for Cu is over 1.5, the EF for Ni and Pb ranges from 0.5 to 1.5, and the EF for Zn and Cd are less than 0.5, indicating Cu is enriched but Zn and Cd are relatively depleted in the BIS. The vertical variations of geochemical properties between Association Ib and IIIb are shown to be clearly different, which seems to be related to the global climate changes such as the shift of Intertropical convergence zone (ITCZ).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.3
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• pp.244-252
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• 2007

A long-term change in the evaporation rate have an influence on the hydrologic processes at the interface between the land surface-air and crop yield. Several previous studies have reported declines in pan evaporation rate, while actual evaporation rate is expected to increase due to anthropogenic global change in the future. The decreasing trend of pan evaporation rate might be involved with global warming and accordingly the trend of annual pan evaporation rate also needs to be checked here in Korea. In this study, 14 points of pan evaporation observation are intensively studied to investigate the trend of pan evaporation for the time period of 1970-2000. Annual pan evaporation is decreasing at the rate of 1.6mm/yr, which corresponds to approximately 50mm for 30 years. Annual pan evaporation rate is larger by $\sim10%$ at the coastal area and decreasing rate is faster as -2.46 mm/yr per year, while that is -0.82 mm/yr per year at the in-land area. The results of the Mann-Kendall trend test shows 4 points are decreasing and 10 points are unchanged with 95% confidence interval. But national annual average values show the decreasing trend of pan evaporation rate as a whole, which corresponds to general trend all over the world. This study will contribute to a variety of studies on water resources, hydrology, agricultural engineering, meteorology, and coastal engineering in association with future global climate change.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.38-49
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• 1986

In order to improve effectiveness of rhizobia-legume symbiotic nitrogen fixation, ecological and physiological characteristics of indigenous rhizobia distributed in Korea soil, that is, the effects of soybean cultivation, physico-chemical properties and climate on the population of indigenous rhizobia and other soil microbes were investigated. The results were summarized as follows: The population of indigenous rhizobia were ranged from $5.1{\times}10^4$ cells to $196.8{\times}10^4$ cells per gram of soil in soybean cultivated soils but from $1.6{\times}10^4$ cells to $78.6{\times}10^4$ cells per gram of soil in soybean un-cultivated soils sampled from 9 different agro-climate zone. The highest population was observed in a soybean cultivated loamy soil from southern part of Korea. The content of available phosphate, exchangeable Ca, Mg, Cu, and B in soil were positively correlated but active Fe, exchangeable Al, Na, and $SO_4$ were inversely correlated to the population of indigenous rhizobia. The inverse relationship was observed between the number of indigenous rhizobia and actinomycetes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.3
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• pp.199-207
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• 2006

Recent global warming seems to be dramatic and has influenced forest ecosystems. Changes in phonology of biota, species distribution range shift and catastrophic climatic disasters due to recent global warming have been observed during the last century. Korean forests located mainly in the temperate zone also have been experienced climatic change impacts including shifting of leafing and flowering phonology, changes in natural disasters and forest productivity, However, little research has been conducted on the impact of climate change on forest ecosystems in Korea which is essential to assess the impact and extent of adaptation. Also there is a shortage in basic long-term data of forest ecosystem processes. Careful data collection and ecological process modeling should be focused on characteristic Korean forest ecosystems which are largely complex terrain that might have hindered research activities. An integrative ecosystem study which covers forest dynamics, biological diversity, water and carbon flux and cycles in a forest ecosystem and spatial and temporal dynamics modeling is introduced. Global warming effects on Korean forest ecosystems are reviewed. Forestry activity and the importance of forest ecosystems as a dynamic carbon reservoir are discussed. Forest management options and challenges for future research, impact assessment, and preparation of mitigating measures in Korea are proposed.

• Journal of the Korean Geographical Society
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• v.44 no.6
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• pp.691-705
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• 2009

Phytolith analysis was made on a 660cm core from Lake Gyeongpo in the East Sea of Korean Peninsula to clarify the environmental change including climate and agricultural characteristics during the Holocene. From the results of phytolith analysis, six phytoliths assemblage zone(PAZ) were recognized from the base to the surface. PAZ I around 5,000 yr BP suggests the transition from the warm and dry to the cool and wet climatic conditions. The climate of PAZ II(ca. 4,000-2,000 BP) was kept on warm, but repeated between dry and wet conditions. PAZ III(2,000~1,000 yr BP) suggests the expansion of agricultural activities under the warm and humid climatic conditions due to the significant phytoliths production of Paniceae and Oryza sativa. While PAZ IV(1,000~500 yr BP) indicates very cool and dry conditions, PAZ V and IV suggest the warm-dry and cool-humid climatic conditions, respectively. Similar to the results of pollen analysis in the lake, the agricultural activities were recognized by PAZ III around 2,000 yr BP from the results of phytolith analysis, and the rice cultivations such as Oryza sativa have been expanded since 2,000 yr BP or later.

• Journal of Korean Society of Disaster and Security
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• v.11 no.2
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• pp.1-8
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• 2018

Extreme climate phenomena are occurring around the world caused by global climate change. The heavy rains exceeds the previous record of highest rainfall. In particular, as flash floods generate heavy rainfall on the mountains over a relatively a short period of time, the likelihood of landslides increases. Gangwon region is especially suffered by landslide damages, because the most of the part is mountainous, steep, and having shallow soil. Therefore, in this study, is to predict the risk of disasters by applying topographic classification techniques and landslide risk prediction techniques to mountain watersheds. Classify the hazardous area by calculating the topographic position index (TPI) as a topographic classification technique. The SINMAP method, one of the earth rock predictors, was used to predict possible areas of a landslide. Using the SINMAP method, we predicted the area where the mountainous disaster can occur. As a result, the topographic classification technique classified more than 63% of the total watershed into open slope and upper slope. In the SINMAP analysis, about 58% of the total watershed was analyzed as a hazard area. Due to recent developments, measures to reduce mountain disasters are urgently needed. Stability measures should be established for hazard zone.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.345-353
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• 2018

Hibernation is regarded as a physiological and behavioral adaptation that permits the survival of animals such as bats during seasonal periods of energy shortage. This study investigated the hibernation period of Plecotus ognevi in the temperate climate zone and the relationship between the thermal preference and hibernating process of bats. We hypothesized that the hibernation period of bats is closely related to the external temperature and temperature preference of bat species in the temperate region. To verify this hypothesis, we surveyed the distribution of the P. ognevi population in South Korea, and the temperature preference and the characteristics of hibernacula of P. ognevi. We predict that hibernation in the bat will begin when the external temperature drops below the thermal preference of the species and will leave from hibernation when the external temperature is higher than the thermal preference. P. ognevi hibernated in roosts maintained in low temperature ambient conditions with $-3.5{\sim}7.5^{\circ}C$). The body temperatures (averaged $3.01{\pm}1.30^{\circ}C$, ranged $0.1{\sim}7.8^{\circ}C$) of hibernating bats were closely related to the rock surface temperatures rather than the ambient temperatures. The bats began to hibernate in late November and final arousals occurred in mid-March, so that the total length of the hibernation was 115~120 days. The period of hibernation was strongly influenced by fluctuations in the external mean temperature. This study suggests that the onset and termination of P. ognevi hibernation is due to the interaction between the temperature of the hibernacula and that of the external environment and is based on the thermal preference of the bats. The study also suggests that the hibernation strategy such as thermal preference and hibernation periods of this species affect to distribution as bat species adapting to a severely climate.