• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.390-397
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• 2021

The time series data of rotifer community focusing on the species number and total density were collected from 29 reservoirs located at Jeonnam Province from 2008 to 2016 quarterly. The reservoirs had similar weather condition during the study period, but their sizes and water qualities were different. To analyze the temporal dynamics of rotifer community, the medians, ranges, outliers and coefficient of variation (CV) value of rotifer species number and abundance were compared. For the temporal trend analysis, time series of each reservoir data were compared and clustered using the dynamic time warping function of the R package "dtwclust". Small-sized reservoirs showed higher variability in rotifer abundance with more frequent outliers than large-sized reservoirs. On the other hand, apparent pattern was not observed for the rotifer species number. For the temporal pattern of rotifer density, COD, phytoplankton abundance fluctuation, and cladoceran abundance fluctuation have been suggested as potential factor affecting the rotifer abundance dynamics.

• Journal of Ecology and Environment
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• v.46 no.3
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• pp.259-272
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• 2022

Background: The Korean Peninsula exhibits a characteristic graded floral distribution, with northern (Manchurian flora) and southern (China-Japan-Korea flora) lineage species coexisting according to climatic and topographical characteristics. However, this distribution has been altered by climate change. To identify ecosystem changes caused by climate change and develop appropriate measures, the current ecological status of the entire Korean Peninsula should first be determined; however, analysis of the current floral distribution in North Korea has been hampered for political reasons. To overcome these limitations, this study constructed a database of floral distributions in both South and North Korea by integrating spatial information from the previously established National Ecological Survey in South Korea and geocoding data from the literature on biological distributions published in North Korea. It was then applied to analyze the current status and distribution characteristics of Manchurian and China-Japan-Korea plant species on the Korean Peninsula. Results: In total, 45,877 cases were included in the Manchurian and China-Japan-Korea floral distribution database. China-Japan-Korea species were densely distributed on Jeju-do and along the southern coast of the Korean Peninsula. The distribution density decreased as the latitude increased, and the distributions reached higher-latitude regions in the coastal areas compared with the inland regions. Manchurian species were distributed throughout North Korea, while they were densely distributed in the refugia formed in the high-elevation mountain regions and the Baekdudaegan in South Korea. In the current distribution of biomes classified according to the Whittaker method, subtropical and endemic species were densely distributed in temperate seasonal forest and woodland/shrubland biomes, whereas boreal species were densely distributed in the boreal forest biome Korean Peninsula, with a characteristic gradation of certain species distributed in the temperate seasonal forest biome. Factor analysis showed that temperature and latitude were the main factors influencing the distribution of flora on the Korean Peninsula. Conclusions: The findings reported herein on the current floral distribution trends across the entire Korean Peninsula will prove valuable got mitigating the ecological disturbances caused by ongoing climate change. Additionally, the gathered flora data will serve as a basis for various follow-up studies on climate change.

• Journal of Wetlands Research
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• v.19 no.1
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• pp.30-36
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• 2017

SS(Suspended Solid) concentration by soil erosion into river at normal and flood season should be measured. However, to present the variation of SS due to various development project such as EIA(Environmental Impact Assessment), River Master Plan, and so on, it is necessary to estimate not measure SS, but there are not exist how to estimate SS. In the present study, therefore, we propose the hydrologic method of estimating SS concentration using the results of particular frequency flood discharge and sediment discharge by RUSLE method. SS consists of silty and clay soil and colloid particle etc. However, in the present study, silty and clay soils of sediment discharge except send set up SS standards. The flow discharge to estimate SS concentration are 1~2 years for normal season, 30~100 years for flood season. Meanwhile, analysis software for probable rainfall uses Fard2006, probable rainfalls under 2-year frequency are estimated using rainfall data and frequency factor of Gumbel distribution. The results of estimating SS concentration using runoff volume by sediment and flow discharges of silty and cray soils as above method show that reliable level of SS concentration is considered in predevelopment of natural condition and under development of barren condition. Especially, SS concentration takes notice that the value of sediment discharge makes a huge difference according to channel slope, it was confirmed that the value obtained by dividing the SS concentration by the channel slope is relatively constant even though the topographical factors are different. Therefore, if the present study will be proceeded for various watersheds, it will be developed as estimation method of SS concentration.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.4
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• pp.176-184
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• 2011

Cold air on sloping surfaces flows down to the valley bottom in mountainous terrain at calm and clear nights. Based on the assumption that the cold air flow may be the same as the water flow, current models estimate temperature drop by regarding the cold air accumulation at a given location as the water-like free drainage. At a closed catchment whose outlet is blocked by man-made obstacles such as banks and roads, however, the water-like free drainage assumption is no longer valid because the cold air accumulates from the bottom first. We developed an empirical model to estimate quantitatively the effect of cold pool on nocturnal temperature in a closed catchment. In our model, a closed catchment is treated like a "vessel", and a digital elevation model (DEM) was used to calculate the maximum capacity of the cold pool formed in a closed catchment. We introduce a topographical variable named "shape factor", which is the ratio of the cold air accumulation potential across the whole catchment area to the maximum capacity of the cold pool to describe the relative size of temperature drop at a wider range of catchment shapes. The shape factor is then used to simulate the density profile of cold pool formed in a given catchment based on a hypsometric equation. The cold lake module was incorporated with the existing model (i.e., Chung et al., 2006), generating a new model and predicting distribution of minimum temperature over closed catchments. We applied this model to Akyang valley (i.e., a typical closed catchment of 53 $km^2$ area) in the southern skirt of Mt. Jiri National Park where 12 automated weather stations (AWS) are operational. The performance of the model was evaluated based on the feasibility of delineating the temperature pattern accurately at cold pool forming at night. Overall, the model's ability of simulating the spatial pattern of lower temperature were improved especially at the valley bottom, showing a similar pattern of the estimated temperature with that of thermal images obtained across the valley at dawn (0520 to 0600 local standard time) of 17 May 2011. Error in temperature estimation, calculated with the root mean square error using the 10 low-lying AWSs, was substantially decreased from $1.30^{\circ}C$ with the existing model to $0.71^{\circ}C$ with the new model. These results suggest the feasibility of the new method in predicting the site-specific freeze and frost warning at a closed catchment.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.64-71
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• 2012

This is a basic study for recovering original form of Nongsanbyeoleop(農山別業) in Gangjin, Jeonnam, created in the latter part of Joseon period and the estimation of originla form at the time of creation was conducted by analyzing related literature and inspecting the actual site. "Joseokruki(朝夕樓記)" of Dasan Jung, Yak Yong could estimate spatial structure and using form of Nongsanbyeoleop and the arrangement of spatial structure in literature could be confirm by on-the-site inspection. The results of this study are as follows. The first, Nongsanbyeoleop managed spatial factors applying natural topography. For the spatial characteristics of Nongsanbyeoleop, the location of ancestral ritual space including deceased father's tomb and tomb house far from the main levee of Yun, Kwang Taek, a father of Yun, Seo Yu by 1.9km and housekeeping could be confirmed. The second, spatial estimation by "Joseokruki" could be possible. "Joseokruki" describes Joseokru.Youngmojae.Hanokkwan.Cheokyunjung.Sangam as construction factors, Wundang.Kookdan.Nokwunoh. as plant factors, Sookyunggan.Keumkoji.Nokeumjung.Uijanghae as hydroponic factors and Pyoeunkok.Aengjakang as natural topography factors. However, most of them were disappeared and at present, only Youngmojae, Keumgoji, Kukdan and Wundang show the past trace. The third is for the changed space of Nongsanbyeoleop and its reason. The surrounding space of Nongsanbyeoleop was planated by land arrangement in 1960s and it played a role of topographical damage because it's recognized as the plane factor including Nongsanbyeoleop's surrounding landscape rather than dotted factor. The forth, the actual measurement of Nongsanbyeoleop and digitalization of manual map of numerical value are judged to be sufficient to apply as the basic material for recovering garden in the future. Because of the diatahce changing method applied at that time, the garden recovery of Nongsanbyeoleop intended to be concreted and 3D model established by digitalized basic materials is considered to apply for multilateral studying. Thus, Nongsanbyeoleop which is byeolseo including the tomb of deceased father based on the conceptual hyo thought shows clear differences from the organized factors of Byolseowonrim of precedent studies and the importance of Byolseowonrim is sufficient. But, the constructional factors which cannot know disappeared spatial factors and accurate location became the limitation of this study. In the future, clear verification of original form must be progressed by excavation which can confirm the location of construction factors.

• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.425-435
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• 2020

This study aims to investigate the impact of the physical structure, such as altitude, slope gradient, slope direction, and topographical structure, and the vegetation pattern, such as existing vegetation, diameter of breast height (DBH), and crown density, on climate. The analysis results showed the significant difference in relative humidity, wind speed, and solar radiation at varying altitudes, the significant difference in all climate factors except for the wind speed at varying slope gradient, and significant difference in temperature and relative humanity at varying slope direction. The topographic structures were divided into valleys, slopes, and ridges. They were found to differ in relative humidity. However, the differences between constant trends and types were found to be insignificant concerning temperature, wind speed, and solar radiation. Significant differences in temperature, relative humidity, and wind speed were recorded with changing existing vegetation. The DBH showed a significant difference in temperature, wind speed, and solar radiation. The crown density showed a significant difference in temperature and solar radiation. The result of the relationship analysis for the analysis of the effect of vegetation pattern and physical structure on the meteorological environment showed that temperature was affected by slope gradient, slope direction, DBH, and crown density. The relative humidity was correlated with the altitude, slope gradient, slope direction, and topological structure in physical structure and the existing vegetation and crow density in vegetation pattern. The wind speed was correlated with the altitude, existing vegetation, and DHB, and the solar radiation was correlated with the slope gradient, DHG, and crown density. The crown density was the most overall significant factor in temperature, relative humidity, and solar radiation, followed by the slope gradient. DBH was also found to be highly correlated with temperature and solar radiation and significantly correlated with wind speed, but there was no statistically significant correlation with relative humidity.

• Journal of Korea Water Resources Association
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• v.34 no.6
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• pp.659-672
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• 2001

Generally, design flood for a hydraulic structure is estimated using statistical analysis of runoff data. However, due to the lack of runoff data, it is difficult that the statistical method is applied for estimation of design flood. In this case, the synthetic unit hydrograph method is used generally and the models such as NYMO method, Snyder method, SCS method, and HYMO method have been widely used in Korea. In this study, these methods and KICT method, which is developed in year 2000, are compared and analyzed in 10 study areas. Firstly, peak flow and peak time of representative unit hydrograph and synthetic unit hydrograph in study area are compared, and secondly, the shape of unit hydrograph is compared using a root mean square error(RMSE). In Nakayasu method developed in Japan, synthetic unit hydrograph is very different from peak flow, peak time, and the shape of representative unit hydrograph, and KICT method(2000) is superior to others. Also, KICT method(2000) is superior to others in the aspects of using hydrologic and topographical data. Therefore, Nakayasu method is not a proper in hydrological practice. Moreover, it is considered that KICT model is a better method for the estimation of design flood. However, if other model, i.e. SCS method, Nakayasu method, and HYMO method, is used, parameters or regression equations must be adjusted by analysis of real data in Korea.

• Korean Journal of Environment and Ecology
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• v.31 no.3
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• pp.297-317
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• 2017

The research has been conducted in order to classify the vegetation types of natural forest in Mt. Janggunbong, Bonghwa-Gun and establish its following characteristics of stands. Vegetation data were collected by June in 2014 to August in 2016. Based on the 71 quadrates, we carried out an analysis of species-area curve, vegetation types, importance value, species diversity, coincidence method and CCA. As a result of the species-area curve, it was showed the proper investigation, vascular plants consisted a total of 227 taxa; 67 families, 152 genera, 197 species, 3 subspecies, 27 varieties. The forest vegetation was classified into 7 vegetation units, when it comes to a community group, they are classified into the Quercus mongolica community group. As for community, Q. mongolica community group is classified into the Acer pictum subsp. mono community, Pinus koraiensis community and Q. variabilis community. As for group, A. pictum subsp. mono community is classified into Lychnis cognata group and Deutzia glabrata group. The P. koraiensis community is classified into A. komarovii group and P. koraiensis typical group. The Q. variabilis community is classified into Parthenocissus tricuspidata group and Q. variabilis typical group. As for subgroup, P. tricuspidata group is classified into P. tricuspidata typical subgroup and Salix caprea subgroup. As a result of the importance value, Q. mongolica showed highest importance value in tree layer of vegetation units 1, 2, 3, 4 and 5. Betula schmidtii showed highest importance value in tree layer of vegetation unit 6. P. densiflora showed highest importance value in tree layer of vegetation unit 7. In subtree layer, shrub layer and herb layer of vegetation units 6 and 7, Q. mongolica and Q. variabilis showed high importance value. This implying that a vegetation units 6 and 7 is predicted to be composed by Q. mongolica and Q. variabilis. As for species diversity, vegetation units 1, 2 and 3 showed high species diversity(2.130~2.353). It was considered to be due to the topographical characteristics of valley. As a result of coincidence method and CCA, altitude showed high correlation than other environmental factor.

• Journal of architectural history
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• v.1 no.1 s.1
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• pp.68-87
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• 1992

This study is the conditions of location according to formed the times in the clan village. The results of this study are as follows ; 1. in the 15th century, the characterestics of the village established residencial place where mountain stream flowed surrounded by the mountain and deep in the mountains with superior quality land. That's because Sa-dae-bu put equal importance on beautiful scenery and practical benefit for living. Stream House provided economical foundation for Sa-dae-bu to be able to keep confucial manners by putting limit their economic status to small medium sized land owner. Topographical condition such as valley or hollow separated from the exterior maintained unification of consanguineous village in self sufficient farming society and held on to independent territory against external to be able to stay away from turbulent days so that they formed residential area of Sa-dae-bu clan. And the valley where flowed clean water was considered as the connection of continuous place where distinctiveness of form in each curve and and factor of calm and dynamic scenery of the clean stream. Scholars in the middle of Chosun Dynasty located in the utopia as place for confucious retirement to study, a place for refinement by combination with the nature or as a way of spacial practice based on Confucious view of nature. 2. in the 16th-l7th century, Most of existing consanguineous villages adopt deep in the mountains for refuge. at that place, upward rank was established by settlement of the ancestor who entered in the village first, the principal was placed in the center of the village and since descendants became numerous, it was serialized as the space of descendants. So, it was arranged in the order of social rank. Most of the villages showed development step by step started from precaution by apperance of the mountain to the lower part. It's because the topography of valley around the village worked as the natural hedge against external force and genealogy of the clan, regularity of social status, order of entrance into the village were reflected into residencial destribution. Also, order of the rank coincided with the one of aspects on geomancy. Genealogical rank within the village represented spacial rank. Houses of descendants and branch families were placed lower than the principal which showed worship to the principal. 3. In 18th century after, as the village was settled nearby cultivated land considering economical loss caused by long distance between residencial area and cultivated land, direction of sect followed by development of village expanded from the front part of the village to the rear part. The principal that was poped out to the front presented frontage over exterior. Therefore, residencial area of branch families expanded to the rear starting from the principal. This represented a slice of social structure at that time. after 18th century, spirit was percieved superior over material, After then, development of cultivation and expantion of land created difference of economic strength within one village. In order to maintain and show off the status of Yang-ban, economic power of indigenous land owner became fundamental, so, sense to worship and to keep the principal became weak eventually. Taking advantage of that situation, residencial area of branch family expanded to the rear part of the principal which showed dual disposition conflicted with each other. However, these clan rules were destroyed and new rules were created after 18th century because of the situation and consciousness at that time.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.39 no.4
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• pp.99-110
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• 2021

This study intends to examine the characteristics of the construction method of the urban water system in the historical cities of Korea, focusing on Gyeongju, Gyeongju, Goryeo, Hanyang, and Suwon Hwaseong, which were created as new towns in the late Joseon Dynasty. It examines the meaning of waterways in connection with the urban skeletal structure, focusing on the location of cities, roads, and arrangement of urban facilities, and analyzes the compositional form of the water system. We tried to derive the relationship with the structure. In particular, it can be seen that water and natural water systems act as key factors in determining the location of a city, and have a close relationship with the urban structure, urban development process, and urban structure. In addition to the symbolic meaning of water in harmony with the geographical concept, realistic demands in terms of water level and water retention are an important background. In order to respond to various demands related to water space, various planning and technical elements for managing water space were introduced in the process of city formation and development. The planning elements of the urban water system in the process of urban formation and development are summarized as follows through the analysis of the research site. First, in the process of building the urban water system in Gyeongju, Goryeo, Goryeo, Hanyang, and Hwaseong, Suwon, which were selected as the research destinations, the water system in consideration of drainage and disaster is common, but the water system construction method and usability are common. shows the difference. Second, water and natural water systems act as symbolic elements to secure the legitimacy of the city location, and as a key factor in determining the location of the city in harmony with the geographical concept and determining the left direction of the city. Third, the natural water system prior to the formation of a city works as a basis for determining the compositional form of the urban water system constructed in the process of urban formation and development in harmony with the topographical conditions. Fourth, the urban water system built on the basis of natural water systems is constructed by linking natural waterways and planned artificial waterways. Fifth, the urban water system is being built in a planned manner in consideration of the utility in connection with the urban structure, such as securing of urban land, arrangement of urban facilities and areas, composition of functional areas, and land division, in addition to the perspective of drainage system and flood control in consideration of disasters.