• Journal of The Geomorphological Association of Korea
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• v.17 no.1
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• pp.59-72
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• 2010

This study is based on the observation on the patterned ground found in the northern part of the Baekdusan during two fieldtrips of 2008 summer. The patterned grounds are found in two areas-Dalmun and Socheonji. The patterned ground found around Dalmun are well-sorted, having fine materials in the center and coarse (boulder size) materials in the rim, and stretching in the form of stairs. Meanwhile, the types of patterned ground found around Socheonji are various, including polygon, stripe, and circular patterns. The particle size analysis and morphological analysis of comprising materials are carried out only for the patterned ground of Socheonji. The mean short and long axis of the patterned grounds are 91cm and 163cm, respectively. The distribution pattern of material size from the most samples increase toward the rim, indicating the patterned grounds are well-sorted. The comprising materials are dominated by silt, which is very susceptible for freeze-thaw cycle. The lower ratio of clay (low less than 10%), suggests that physical weathering is more dominant rather than chemical weathering. The involution structure found in the vertical section of the patterned grounds is likely to have formed by active cryoturbation which is one of the dominant geomorphic processes in the periglacial environments like the study area.

• Korean Journal of Environment and Ecology
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• v.32 no.5
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• pp.486-496
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• 2018

In this study, we have selected Larix kaempferi as a study area in Woraksan National Park for understanding the ion index according to the difference of topography in national parks. We measured the weather and ion at two fixed points, ridge and valley, where the Larix kaempferi dominates in the same ecological structure in Woraksan National Park. The weather measurement results showed the average, maximum, and minimum temperatures of $28.22^{\circ}C$, $29.9^{\circ}C$, and $26.4^{\circ}C$, respectively at the ridge. The average, maximum, and minimum temperatures at the valley were $27.08^{\circ}C$, $27.8^{\circ}C$, and $25.5^{\circ}C$, respectively. The average, maximum, and minimum relatively humidities at the ridge were 67.02%, 75.25%, and 61.95%, respectively. he average, maximum, and minimum relatively humidities at the valley were 69.74%, 76.8%, and 63.75%, respectively. The average, maximum, and minimum amounts of positive ions generated in the ridge was $698.40{\pm}59.80ea/cm^3$, $885.88ea/cm^3$, and $597.88ea/cm^3$, respectively. The average, maximum, and minimum amounts of negative ions generated in the ridge were $736.07{\pm}83.89ea/cm^3$, $934.53ea/cm^3$, and $599.32ea/cm^3$, respectively. The ion index is calculated to be 1.06. The average, maximum, and minimum amounts of positive ions generated in the valley were $1,732.49{\pm}354.08ea/cm^3$, $2,652.10ea/cm^3$, and $1,110.92ea/cm^3$, respectively. The average, maximum, and minimum amounts of negative ions generated in the valley were $1,990.47{\pm}433.57ea/cm^3$, $3,126.75ea/cm^3$, and the minimum value was $1,352.17ea/cm^3$. The ion index is calculated to be 1.16. The difference in the amount of negative ions generated in ridge and valley was $1089.26ea/cm^3$, and the difference of the calculated ion index between the ridge portion and the valley portion was 0.10. The results of this study were provided as the reference weather data of national parks for health management.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.333-343
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• 2015

This research aims at identifying the goshawk's possible and replaceable breeding ground by using the MaxEnt prediction model which has so far been insufficiently used in Korea, and providing evidence to expand possible protection areas for the goshawk's breeding for the future. The field research identified 10 goshawk's nests, and 23 appearance points confirmed during the 3rd round of environmental research were used for analysis. 4 geomorphic, 3 environmental, 7 distance, and 9 weather factors were used as model variables. The final environmental variables were selected through non-parametric verification between appearance and non-appearance coordinates identified by random sampling. The final predictive model (MaxEnt) was structured using 10 factors related to breeding ground and 7 factors related to appearance area selected by statistics verification. According to the results of the study, the factor that affected breeding point structure model the most was temperature seasonality, followed by distance from mixforest, density-class on the forest map and relief energy. The factor that affected appearance point structure model the most was temperature seasonality, followed by distance from rivers and ponds, distance from agricultural land and gradient. The nature of the goshawk's breeding environment and habit to breed inside forests were reflected in this modeling that targets breeding points. The northern central area which is about $189.5 km^2$(2.55 %) is expected to be suitable breeding ground. Large cities such as Cheongju and Chungju are located in the southern part of Chungcheongbuk-do whereas the northern part of Chungcheongbuk-do has evenly distributed forests and farmlands, which helps goshawks have a scope of influence and food source to breed. Appearance point modeling predicted an area of $3,071 km^2$(41.38 %) showing a wider ranging habitat than that of the breeding point modeling due to some limitations such as limited moving observation and non-consideration of seasonal changes. When targeting the breeding points, a specific predictive area can be deduced but it is difficult to check the points of nests and it is impossible to reflect the goshawk's behavioral area. On the other hand, when targeting appearance points, a wider ranging area can be covered but it is less accurate compared to predictive breeding point since simple movements and constant use status are not reflected. However, with these results, the goshawk's habitat can be predicted with reasonable accuracy. In particular, it is necessary to apply precise predictive breeding area data based on habitat modeling results when enforcing an environmental evaluation or establishing a development plan.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.151-164
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• 2022

According to the records of historical and instrumental earthquakes, the southeastern part of the Korean Peninsula is considered the highest seismic activity area. Owing to recent reports of numerous Quaternary faults along the Yangsan and Ulsan fault zones, paleoseismological studies are being actively conducted in these areas. The study area is located in the central part of the Ulsan fault zone, where the largest number of active faults have been reported. Based on lineament and geomorphic analysis using LiDAR images and aerial photographs, fault-related landforms showing topographic relief were observed and a trench survey was conducted. The trench length 20 m, width 5 m, depth 5 m is located approximately 300 m away to the northeast from the previously reported Malbang fault. From the trench section, we interpreted the geometric and kinematic characteristics of the fault based on the deformed features of the Quaternary sedimentary layers. The attitude of the reverse fault, N26°W/33°NE, is similar to those of the reported faults distributed along the Ulsan fault zone. Although a single apparent displacement of approximately 40 cm has been observed, the true displacement could not be calculated due to the absence of the slickenline on the fault plane. Based on the geochronological results of the cryogenic structure proposed in a previous study, the most recent faulting event has been estimated as being earlier than the late Wurm glaciation. We interpreted the thrust fault system of the study area as an imbrication structure based on the previous studies and the fault geometry obtained in this additional trench. Although several previous investigations including many trench surveys have been conducted, they found limited success in obtaining the information on fault parameters, which could be due to complex characteristics of the reverse fault system. Additional paleoseismic studies will contribute to solving the mentioned problems and the comprehensive fault evolution.

• Journal of the Korean Geographical Society
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• v.30 no.2
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• pp.103-119
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• 1995

This Paper aims to compare the lower marine terraces distributed from Muckho to Gangneung in the mid-eastern coast of Korean peninsula by the geomorphic method of using characteristies of terrace features and terrace deposits, paleosol, and fossil cryogenic structures, and to estimate the age of the lower marine terraces on the basis of the comparisons of those with the characteristics of thalassostatic terrace in adjacent rivers. The 1ower marine terraces in this area can be classified into two levels, i.e., lower marine terrace I and II surfaces, in desending order, according to the difference of former shoreline altitude. The former shoreline heights of the lowerm marine terrace I and II surfaces are 18m and 10m, respectiveiy. The width of the I surface is broader and distributed more continuousiy than that of II surface. Daejin I surface in Muckho coast, and Myeongju and Anin terrace in Gangneung coast could be classified into the lower marine terrace I surface, and Daejin II surfaCe into II surface. The Surface of ancient shore platform of the lower marine terrace I and II surfaces were weathered, and the color of the terrace deposit ranges from red to reddish brown. And this terrace deposit is covered with slope deposit of Last Glacial or fossil periglacial structures (platy structure and vecicle) of Last Glacial are formed in terrace deposit. These facts indicate that the lower marine terrace I and II surfaces had been formed before the Last Glacial, and then affected by chemical weathering under warm environment, finally followed by cold period. But the deposit of the lower marine terrace I surface is more weathered than that of II surface. And pseudogleyed red soil, which is developed in I but not in II surface, could be judged to have been formed in the Last Interglacial culmination stage (Oxygen isotope stage 5e). Therefore, in terms of the degree of weathering of the terrace deposit and the existence of pseudogleyed red soil, the age of both terrace is thought to be a little different. And the characteristics of the above mentioned II surface are accord with those of thalassostatic terrace formed in middle or late period of the Last Interglacial (5e or 5a). Thus on the basis of above all points, the lower marine terrace I and II surfaces in this area could be seen to have formed in the Last Interglacial culmination stage and middle or late period of the Last Interglacial, respectively. Because the lower mamine terrace I surface is broadry distributed in the eastern coast of Korea nPeninsula, the surface could be used to be a key surface in studying Quaternary marine terraces.