• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.598-601
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• 2007

Urban growth management is essential for sustainable urban growth. Monitoring physical urban built-up area is a task of great significance to manage urban growth. Detecting urbanized area is essential for monitoring urbanized area. Although image classifications using satellite imagery are among the conventional methods for detecting urbanized area, they requires very tedious and hard work, especially if time-series remote sensing data have to be processed. In this paper, we propose an effective urbanized area detecting method based on normalized difference vegetation index (NDVI) and normalized difference built-up index (NDBI). To verify the proposed method, we extract urbanized area using two methods; one is conventional supervised classification method and the other is the proposed method. Experiments shows that two methods are consistent with 98% in 1998, 99.3% in 2000, namely the consistency of two methods is very high. Because the proposed method requires no more process without band operations, it can reduce time and effort. Compared with the supervised classification method, the proposed method using vegetation indices can serve as quick and efficient alternatives for detecting urbanized area.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.4
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• pp.96-105
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• 2010

The purpose of this study is to offer raw data on managing naturalized plants and the ecological characteristics of urban streams by researching the naturalized plants distributed in Naedong Stream, Changwon-si. The results are as follows. The numbers of naturalized plants were summarized as 45 taxa: 18 families, 38 genera, 43 species and 2 varieties. There were 3 taxa of invasive alien plants: Rumex acetocella, Ambrosia artemisiifolia var. elatior and Sicyos angulaus. In an analysis of life forms, there were 2 taxa of megaphanerophytes, 1 taxa of nanophanerophytes, 3 taxa of chamaiphytes, 7 taxa of hemicryptophytes, 1 taxa of geophytes and 31 taxa of therophytes. The urbanized and naturalized indices were 16.6% and 25.1%, respectively. The results of an analysis by vertical structures showed that naturalized plants included 30 taxa upstream, 42 taxa midstream and 32 taxa downstream. For the urbanized index, upstream was 11.1%, 15.5% in midstream and 11.8% in downstream. For the naturalized index, upstream was 21.7%, 33.3% in midstream and 37.2% in downstream. An analysis of crossing structures showed at taxa of 39 naturalized plants on bank. 30 taxa along the riverside and 7 in the water. For the urbanized index, banks were 14.4%, riverside 11.1% and waterside 2.6% while the naturalized index included 30.5% on the banks, 30.6% along the riverside and 20.0% in the water. As regards the management of naturalized plants, because Remex acetocella, Ambrosia artemisiifolia var. elatior and Sicyos angulaus have a negative impact on the ecosystem, they need to be efficiently controlled.

• Journal of Environmental Impact Assessment
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• v.20 no.1
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• pp.1-11
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• 2011

This study was carried out to suggest the baseline data necessary for vegetation restoration at riverine wetland within stream corridor. We used the prevalence index for wetland assessment by applying the method of weighted averages with index values based on five hydrophyte indicator status as defined by estimated probability occurred in wetland. We selected near nature and urbanized reach of Gap and Yanghwa streams as experimental site. Although two sites have some different disturbance and characteristics of watershed, they showed that similarity of vegetation community including three dominant species - Salix koreensis, Phragmites communis, Miscanthus sacchariflorus - was very high. But in case of Yanghwa stream, various kinds of emergent plants along wetted condition were distinctly occurred, resulted from difference of hydrological regime and substrate, etc. Degree of naturalness of vegetation at the sampled areas indicated that near nature area of Gap stream and all area of Yanghwa stream were fitted as riverine wetland, while urbanized area of Gap stream has changed into upland condition. In conclusion assessment system using prevalence index would be considered an effective method for evaluating of natural states of riverine wetland, but further integrated consideration of physical, hydrological, and biological factors of stream process, and also with considering the difference between those qualitative data of vegetation community.

• Journal of Environmental Science International
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• v.30 no.10
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• pp.779-787
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• 2021

This study analyzes structural landscape changes over a time-series for a small and medium-sized city, Gangneung-Si, based on area and distribution patterns, and according to the type of land cover. Among the types of land cover, the area ratio of urbanized areas increased by 2.02% in the late 2010s as compared to the late 1980s, while there was a decrease of 2.69% in farmland and 0.69% in grassland areas. On analyzing the changes in land cover use by applying the Fragstats program, it was confirmed that landscape changes in urban and management areas were relatively severe according to the Landscape Shape Index, Largest Patch Index, and Aggregation Index. A pattern of concentrated expansion was also found around certain areas. In particular, from the analysis, it was established that the proportion of urbanized area had considerably increased and that the extent of farmland damage to management areas, including planned management areas, was large. Additionally, the Total Core Area generally indicated a reduction in the core areas of farmland and forest within urban and management areas. A medium-sized city showed significant changes besides large cities in terms of landscape structure. The developmental pressure on management areas, in particular, was quite high.

• The Korean Journal of Ecology
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• v.21 no.5_3
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• pp.603-631
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• 1998

Flora and distribution of vascular plants included introduced species of Mt. Nam park in Seoul were investigated from 1997 to 1998. The flora was composed of 112 families, 338 genera, 487 species, 1 subspecies, 60 varieties, 11 forma or 559 taca. Whole taxa of Mt. Nam calculated with the other reports were recorded 125 families, 461 genera, 832 species, 2 subspecies, 115 varieties, 14 forma or 963 taxa. Mt. nam area has lost its properties because of road and promenade construction, several park reclaimation, introduction of foreign species and exotic plants, and so on. The urbanized index (UI) was comparatively high at 18.3%. Eupatorium rugosum which shown high shade tolerance comparatively was occupied dominantly in road sides. The natural ecosystem and biodiversity of Mt. Nam were under threatened by introduced species. DBH mode of Pinus densiflora community was shown bell shape but that of Quercus mongolica was shown reverse J shape, therefore, it will be occupied in the future this area dominantly by Q. mongolica community. However the vegetation of Mt. nam park area are repressing by superior position in their growth of introduced species included R. pseudo-acacia, Ailanthus altissima and E. rugosum, etc.

• Korean Journal of Remote Sensing
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• v.35 no.6_4
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• pp.1403-1415
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• 2019

Urban population growth and consequent rapid urbanization involve some thermal environmental problems in the cities. Monitoring of thermal environments in urban areas such as hot spot analysis is required for effective actions to resolve these problems. This study selected 14 dongs and surrounding administrative districts of Sejong city as study areas and analyzed the characteristics of changes in surface temperature due to the urban expansion in the summer from 2013 to 2018. In the study, the surface temperature distributions in the study areas were plotted using surface temperature values from Landsat 8 and NDVI (Normalized Difference Vegetation Index) and NDBI (Normalized Difference Built-up Index) based on KOMPSAT 2/3 data, and the patterns of surface temperature changes with urban expansion were discussed using the estimated NDVI and NDBI. In particular, the distinct urbanization in the study areas were selected for case studies, and the cause of the changes in the hot spots in the regions was analyzed using high-resolution KOMPSAT images. This study results present that hot spots appeared in urbanized regions within the study areas, and it was plotted that the lower the NDVI values and the higher the NDBI values indicate the temperature values are high. The land surface temperature and satellite-based products were used to divide the study areas into continuously urbanized regions and rapidly urbanized regions and to identify the different characteristics depending on land covers. In the regions with distinct surface temperature changes by urbanization, the analysis using high-resolution KOMPSAT images as presented in this study could provide effective information for urban planning and policy utilization in the future.

• Journal of People, Plants, and Environment
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• v.23 no.3
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• pp.293-304
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• 2020

Background and objective: This study was carried out to assess the relationship between the internal and external environments and the ecological items in five sites with a high level of artificial use intensity prior to the establishment of Geumgang River riparian ecological belts. Methods: The sites were classified into forest type, cultivated land type and urbanized type in accordance with their respective locational types. Ecological items including plant ecology such as proportion, naturalization index and urbanization index of native species were analyzed and animal ecology such as the number of species and population of wild birds, amphibians and reptiles, mammals, and butterflies and dragonflies, which are indicator insects, were investigated. In addition, species diversity indices of wild birds, butterflies and dragonflies found in all the subject lands were computed. Results: Among the plant ecological items, the ratio of native species in the forest type was higher than 90%, which was a satisfactory level, while the naturalization and urbanization indices were less than 10%. The number of species in the animal ecological characteristics was reduced in the order of forest type, cultivated land type and urbanized type. As the results of correlation analysis, the internal area of the planted area showed a negative correlation with the total of individuals. The area of grasslands showed a positive correlation with the number of dragonfly species and the total number of individuals, thereby illustrating that wet grasslands have positive effects. The area of surrounding forests, as an external environment, had a negative correlation with the urbanization index (UI) but a positive correlation with the inhabitation of butterflies and the total number of species. Conclusion: The results confirmed the need for more diversified special compositions including planted land, grassland, wetland, bodies of water and waterways within the subject land in the wetland ecological belt along with the need for surrounding forest location and preservation from the perspective of purchase and restoration of land for enhancement of wider biodiversity in the future.

• Ecology and Resilient Infrastructure
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• v.6 no.2
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• pp.79-88
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• 2019

In order to study the water quality status and its causal environmental factors, the water quality variables of chemical oxygen demand (COD), chlorophyll a (Chl a), Total phosphorus (TP), and total nitrogen (TN), the hydrogeomorphologic variables of water level fluctuation, total water storage, dam elevation, watershed area, and shoreline development index, and the land cover variables of forest, agricultural area, and urbanized area in the watershed were investigated in total 73 reservoirs with various operational purposes, water level fluctuation and geographical distribution in South Korea. The water quality was more eutrophic in the reservoirs of the more urbanized and agricultural area in the watershed, the low altitude, the narrow water level fluctuation, the narrowed watershed area, and the more circular shape. In terms of the purposes of reservoir operation, the reservoirs for agricultural irrigation were more eutrophic than the reservoirs for flood control. The results of the variable selection and path analysis showed that COD determined by Chl a and TP was directly affected by water level fluctuation and the shoreline development of the reservoirs. TP was directly affected by the urbanized area of the watershed which was related to the elevation of the reservoir. TP was also influenced by the water level fluctuation and the shoreline development. In conclusion, the eutrophication of the reservoirs in Korea would be influenced by the land use of the watershed, hydrological and geographical characteristics of the reservoir, water level fluctuation by the anthropogenic management according to the reservoir operation purpose, and the location of the reservoirs.

• Journal of Environmental Impact Assessment
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• v.5 no.2
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• pp.33-47
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• 1996

To select the criteria, literature review was made in the quantitative case of conservation biology, foreign country's EIA and domestic ecology. Among them, a few factors was extracted. To applicate the criteria to domestic forest ecosystem, expert opinion survey was executed to the ecologist. The results were summarized as follows; 1. Classification of sites was made of land use system which is related to forest ecosystem or forest conservation. Sites are divided into 3 categories which are nature preservation area, seminature preservation area and urbanized area. Evaluation criteria is consisted of rarity and naturalness. 2. Each area had different criteria composition according to the site characteristics. Criteria of nature preservation area is rarity in the broad sense (distribution pattern of vegetation), vegetation size, successional stage and depth of organic matters. Those of seminature preservation area are rarity in the broad sense (distribution area of vegetation), vegetation size, successional stage, diameter at breath height and depth of organic matters. And those of urbanized area are vegetation distribution in area, successional stage, age of forest and diameter of breath height. The basic data of criterion was gathered by field survey. 3. Evaluation index and total naturalness index was obtained by adding the each criterion. It is made up of two categories-rarity and naturalness. TNi is divided into 3 grades. Grade I is more than 70% for TNi, grade IT is 50~70%, and grade III is below 50%. According to the each grade, permitted action and facilities were suggested.. This research just focuses on the evaluation of vegetation quality and the assessment results do not directly judge conservation or development. To make better evaluation criteria, various fields of forest ecosystem-geological or physical nature environment and fauna ecosystem etc. -will be added wholly to this research.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.535-545
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• 2011

This study was carried out to suggest the baseline data necessary for vegetation restoration by naturalness assessment of riverine wetland within stream corridor. We selected stream reach both of near nature and urbanized by Nonsan stream and Hongchun river as experimental site. Composition of vegetation community and land use pattern between two sites indicated considerable difference, which imply for many different watershed property and process disturbed each other at river ecosystem. Naturalness of the sampled reaches showed that near nature is in better condition for riverine wetland than urbanized of all two sites. However, the prevalence index of Hongchun river within its natural state was lower than that of Nonsan stream, because the index included some vegetation communities occurred at upland fringe and bank slope. In conclusion assessment system using prevalence index would be considered an effective method for evaluating of natural states of riverine wetland.