• Korean Journal of Environment and Ecology
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• v.37 no.4
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• pp.289-301
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• 2023

Forests within watersheds are essential in maintaining ecosystems and are the central infrastructure for constructing an ecological network system. However, due to indiscriminate development projects carried out over past decades, forest fragmentation and land use changes have accelerated, and their original functions have been lost. Since a forest's structural pattern directly impacts ecological processes and functions in understanding forest ecosystems, identifying and analyzing change patterns is essential. Therefore, this study analyzed structural changes in the forest landscape according to the time-series land cover changes using the FRAGSTATS model for the dam watershed of the Geum River upstream. Land cover changes in the dam watershed of the Geum River upstream through land cover change detection showed an increase of 33.12 square kilometers (0.62%) of forests and 67.26 square kilometers (1.26%) of urbanized dry areas and a decrease of 148.25 square kilometers (2.79%) in agricultural areas from the 1980s to the 2010s. The results of no-sampling forest landscape analysis within the watershed indicated landscape percentage (PLAND), area-weighted proximity index (CONTIG_AM), average central area (CORE_MN), and adjacency index (PLADJ) increased, and the number of patches (NP), landscape shape index (LSI), and cohesion index (COHESION) decreased. Identification of structural change patterns through a moving window analysis showed the forest landscape in Sangju City, Gyeongsangbuk Province, Boeun County in Chungcheongbuk Province, and Jinan Province in Jeollabuk Province was relatively well preserved, but fragmentation was ongoing at the border between Okcheon County in Chungcheongbuk Province, Yeongdong and Geumsan Counties in Chungcheongnam Province, and the forest landscape in areas adjacent to Muju and Jangsu Counties in Jeollabuk Province. The results indicate that it is necessary to establish afforestation projects for fragmented areas when preparing a future regional forest management strategy. This study derived areas where fragmentation of forest landscapes is expected and the results may be used as basic data for assessing the health of watershed forests and establishing management plans.

• Korean Journal of Remote Sensing
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• v.33 no.5_3
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• pp.835-854
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• 2017

Government regulations and policies are important means of restraining the indiscreet expansion of urban areas. According to the standards from those means, it is clear that the fluctuation of forest green proportion encroached by the increase of urban space is obvious. In this study, we interpreted the changes of urban areas as well as the green ones owing to the urban expansion by the decades from 1996, with focusing on the cities of Seoul and Daegu highly developed in South Korea. The purpose of this study is to analyze the spatial expansion and morphological characteristics of urban land cover using not only satellite imageries (1996, 2006, 2016). but also the urban expansion intensity index (UEII) and GUIDOS program. Ultimately, this study is to compare the changes in the rate of forests due to urban expansions annually analyzed based on areas of forest elevation, slope, and the area of single forest patch. In Seoul, the expansion begun from urban space to suburban areas was comparatively rapid, which led the forest fragmentation and the gradual decline of the single patch. However, when it comes to DEM (Digital elevation model) and slope above a certain standard, by the development regulations, there was little decrease in area by anthropogenic developments. The city of Daegu has increased at a slow speed since 1996 in urban and suburban areas, whereas green forests have greatly increased through green forest conservation campaigns. In this way, as to the government policies and regulations, the quantitative and morphological expansion of cities owing to development could be controlled and forest spaces could be preserved as well. Therefore, regulations and policies by the government should be appropriately utilized for sustainable cities.

• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.53-62
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• 2015

We surveyed butterfly community in a rural area of the southwestern part of Korea to investigate the changes of species composition and their abundances between 2001~2002 and 2014. The butterfly survey was conducted at the same site using a line transect method. There was a significant decrease of the numbers of species and individuals between 2001~2002 and 2014. We categorized each species based on six ecological traits: habitat type, habitat breadth, food plant type, food plant breadth, number of generation per year and overwintering stage. The comparison of number of species using these ecological traits showed no difference during the 10-yr time intervals. However, the comparison of number of individuals for the ecological traits showed the significant differences except for one trait, overwintering stage. We could suspect that the decrease of butterflies in the study area was resulted from the habitat change. To investigate the causal factors and the changes of butterfly fauna, we need a long-term monitoring of the local butterfly community.

• Journal of Korean Society of Transportation
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• v.23 no.6 s.84
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• pp.7-18
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• 2005

Currently, design speed selection is chosen by highway function, terrain type and area type. But some standards in classifing highway function let designer decide design speed in an arbitrary manner and too rough a highway function classification system leads to a road function which can not reflect road design, and some ambiguity of terrain type leads to a road which can not reflect land use pattern. Highway design based on traffic volume level without considering area type can result high construction cost. This research paper provides new highway design standards which are based on the refinement of highway design speed selection procedure. The new design speed is summarized to be determined by a more detailed highway function, terrain type, and area type that were made considering South Korean characteristics. The new highway function is established by adopting highway function reclassification and design volumes and rural town center reclassification and new design standards for terrain type selection are developed in this research by analyzing South Korean GIS Data Base obtained over the national government offices.

• The Korean Journal of Ecology
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• v.24 no.6
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• pp.385-394
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• 2001

An attempt to clarify the landscape structure of urban areas was carried out in the greenbelt around Seoul, Korea's metropolis. By means of aerial photographs and a field survey, a vegetation map including land-use pattern was made. Landscape structure was described by analyzing this vegetation map and the results of phytosociological survey. Landscape element types identified were (1) secondary forest, (2) plantation, (3) cultivated field, (4) urbanized area, (5) graveyard, and (6) bare rock. Vegetation units, resulting from the phytosociological analysis, included Quercus mongolica, Q. variabilis, Q. acutissima, Pinus densiflora, Q. aliena, and Alnus japonica communities. Plantations were composed of Robinia pseudoacacia, Populus tomentiglandulosa, P. rigida, Larix leptolepis, P. koraiensis, and Castanea crenata stands. Patches near to human settlements in the lower zones of the mountains were fragmented and small but they became larger towards the higher mountain zones. On the other hand, the number of patches was fewer and their size was larger in Mt. Cheonggye more distant from the principal residential area, larger in size, and higher in elevation compared with the other 2 mountains, Mt. Daemo and Mt. Acha. Floristic composition of Mongolian oak(Q. mongolica) stand distributing in the upper part of each mountain, in which artificial interference is rare, showed a difference among those study areas different in parent rock and disturbance regime. But that of black locust(R. pseudoacacia) stand located in lowland of mountainous area, in which artificial interference is frequent was similar to each other. As the results of analyses on the frequency distribution of diameter classes of major species, dominant landscape elements, Mongolian oak forest showed different responses depending on artificial interference as continuous maintenance and retrogressive succession in the sites far from and near to the residential areas, respectively. On the other hand, black locust stands showed a probability to be restore to the native oak forest through progressive succession.

• Journal of Environmental Science International
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• v.17 no.2
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• pp.149-162
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• 2008

Aquatic and riparian vegetation of river ecosystems are very important both in ecological and management perspectives. Vegetation surveys were conducted to understand the characteristics of riparian vegetation in the mid and lower reaches of the Nakdong River, Korea. A total of 68 families and 260 species were identified at eleven survey sites. The numbers of taxa were similar to those reported in a previous survey in 1996,but the percentage of naturalized plants increased more than two times compared to that in the previous survey. Survey sites near Yangsan Bridge and Nambu Park in Yangsan showed the highest percentage of naturalized plant species. Urbanization indices of the survey sites were high at 18.8% on average. Therophytes were the most dominant plant life form at the survey sites with 39.2% of total plants identified, followed by phanerophytes (19.2%), hemicryptophytes (18.9%), aquatic plants (13.9%), cryptophytes (5.8%), and chamaephytes (3.1%). The relative composition of hemicryptophytes decreased whereas those of therophytes and chamaephytes increased compared to those in the survey in 1996. This may be due to increase in dryness of riparian soils or degradation of riparian areas. Plant compositions at sites near Jeokpo Bridge and Hwoicheon suggest that the composition and distribution of riparian vegetation are affected by land use pattern surrounding riparian areas or human accessibility to the areas.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.515-522
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• 2011

This study examined the epiphytes using stable isotopes. Separated epiphytes should represent the water quality. In study areas, where agricultural paddies were prevailing, biomass of epiphytes can increase nitrogen isotopes(${\delta}^{15}N$) and as a result decrease in carbon isotopes(${\delta}^{13}C$). Naerin stream and Inbuk upper areas showed higher nitrogen isotopes(${\delta}^{15}N$) than in Hangye and Buk stream. Also, stable carbon isotopes(${\delta}^{13}C$) in Naerin stream and Inbuk streams tended to increase than in Hangye and Buk stream. This can indicate the epiphytes can be a good indicator for water quality pollution.

• Journal of Ecology and Environment
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• v.33 no.4
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• pp.289-298
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• 2010

A number of characteristics of the Lake H$\ddot{o}$vsg$\ddot{o}$l watershed, such as the lake's location at the edge of the Central Asian continuous permafrost zone, provide a unique opportunity to evaluate possible anthropogenic impacts in this remote area in northern Mongolia. In this study, we compared stream solute concentrations in six sub-watersheds in the Lake H$\ddot{o}$vsg$\ddot{o}$l watershed. Water samples were collected during the summer months between 2003 and 2005. Concentrations of $Cl^-$ ranged from 9.8 to $51.3\;{\mu}mol/L$; average nitrate concentrations were very low and ranged from undetectable to $1.1\;{\mu}mol/L$ and average ${SO_4}^{2-}$ concentration at sampling stations with minimal animal grazing ranged from 66 to $294\;{\mu}mol/L$. Average dissolved organic carbon (DOC) concentrations ranged from 642 to $1,180\;{\mu}mol$ C/L. We did not find statistically significant differences in DOC concentrations among the six streams, although DOC concentrations tended to be higher in the two northernmost streams, possibly related to differences in the active layer above the permafrost. Dissolved organic nitrogen (DON) concentrations were correlated with DOC concentration, and followed the same spatial pattern as those for DOC. In streams in this remote watershed, total dissolved nitrogen was made up of mostly organic N, as has been found for other regions distant from anthropogenic N sources. Overall, these results suggest that future research on the dynamics of DOC and DON in this watershed will be especially insightful in helping to understand how changes in climate and land use patterns will affect transformations, retention, and export of dissolved organic matter within these sub-watersheds in the Lake H$\ddot{o}$vsg$\ddot{o}$l region.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.2
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• pp.39-51
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• 2018

Long-term unexecuted urban parks will be released from urban planning facilities after 2020, this may result in development of those parks. However, little research have been focused on how to develop those parks considering conservation, development, spatial pattern, and so on. Therefore, in this study, we suggested an optimization planning model that minimizes the fragmentation while maximizing the conservation and development profit using ACO (Ant Colony Optimization). Our study area is Suwon Yeongheung Park, which is long-term unexecuted urban parks and have actual plan for private development in 2019. Using our optimization planning model, we obtained four alternatives(A, B, C, D), all of which showed continuous land use patterns and satisfied the objectives related to conservation and development. Each alternative are optimized based on different weight combinations of conservation, development, and fragmentation, and we can also generated other alternatives immediately by adjusting the weights. This is possible because the planning process in our model is very fast and quantitative. Therefore, we expected our optimization planning model can support "spatial decision making" of various issue and sites.

• Journal of Korea Soil Environment Society
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• v.1 no.1
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• pp.39-46
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• 1996

For the purpose of development of bioremediation technology for soil contaminated by chlorinated phenols, this study was focused on the isolation and characterization of bacteria capable of degrading chlorinated phenols, the establishment of analytical methods for chlorinated phenols, and the investigation of the contaminated sites. One site near the Incheon Industrial Complex was identified as a pentachlorophenol (PCP)-contaminated spot. The soil brought from the PCP-contaminated site contained 10-100$mu\textrm{g}$/g wet soil of PCP. Many bacterial strains capable of growing on a minimal medium containing PCP were isolated from 15 soil samples collected throughout the land, and among them, 10 active isolates were finally selected for the further studies on the biodegradability and for the use in in situ bioremediation of contaminated soil. These isolates showed species-specific pattern in PCP-decrease and cell growth in a minimal medium containing 500-1,000mg/ιPCP. Strain Bul degraded 90% of PCP at 216 hrs after incubation. Expecially, strain Bu34 was capable of degrading 4,000mg/ι PCP and was identified as Pseudomonas putida Bu34. It is seemed that the isolated active bacteria could be effectively used for the bioremediation of PCP-contaminated sites.