• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.3
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• pp.1033-1041
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• 2014

Rapid urbanization of Korea was an unprecedented example in the world and urban population increased significantly. As a result, unbalanced distribution of population is serious problem in Korea because approximately 50% of the population is concentrated in the capital area that is 10% of nation's territory, thereby occurring various urban problems including UHI. Hence, Sejong Special Autonomous City was inaugurated officially on 2 July 2012 in order to decentralize population of capital area and induce more balanced regional development. The Sejong City has been changed drastically over a period of years as developed practically since the late 2000's and is expected to have new problems of urbanization. The land cover change due to urbanization is the main cause of UHI that urban area is significantly warmer than its surrounding areas and UHI is not only affecting urban climate change but also natural environment. So the purpose of this research is to analyze level of urbanization and UHI effect and to provide the correlation analysis between Land Surface Temperature and spectral indices. To achieve this, satellite imagery from LANDSAT were used. NDVI, NDBI, and UI were calculated using red, near-infrared, mid-infrared ($0.63{\mu}m-1.75{\mu}m$) images and LST was retrieved utilizing thermal infrared ($10.4{\mu}m-12.5{\mu}m$) image. Based on each index and LST, Changes of NDVI, UI and UHI through TVI were analyzed in Sejong City. UHI effect increased around newly constructed multi-functional administrative city, the correlation between LST and NDVI was negative and UI was strong positive.

• Korean Journal of Environment and Ecology
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• v.21 no.1
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• pp.1-12
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• 2007

Nauralized plants in Ulleungdo were enlisted as 65 taxa, 21 families,49 genera,63 species and 2 varieties by field survey and flora lists of literature cited. Family Compositae covered 27.7% and Family Gramineae, Family Leguminosae and Family Polygonaceae covered 7.7% each. In this study, the nine taxa such as Rumex nipponicus, Trifolium campestre, Oxalis articulata, Anthriscus caucalis, Ipomoea purpurea, Coreopsis Ianceolata, Galinsoga parviflora, Tritonia crocosmaeflora and Festuca arundinacea are added as Nauralized plants in Ulleungdo. Annual plants ratio is 36.9% by life-form spectrum and Europe ratio is 40.0% by origin. The Urbanization Index was 22.0 and the Ratio of Naturalized has increased by flora lists of literature cited each. Ambrosia artemisiifolia var. elatior is growing in Ulleungdo by a plant cause disturbance. Spread prevention and minimization incoming of gardening plants by management plan of naturalized plants might be required. Moreover, it is needed to induce the succession for the recovery of the cut-slope using the native plants.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.3
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• pp.9-20
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• 2009

The naturalized plants in the Gwangyang Steel Works were listed 70 taxa; 18 families, 51 genus, 66 species, 3 varieties and 1 form. by field survey. The naturalized plants divided into pattern by survey of annual plants ratio is 31 taxa (44.3%) by life form spectrum and perennials is 23 taxa (32.9%), biennials is 13 taxa (18.5%), two trees (Robinia pseudoacacia, Alianthus altissima) and one shrub (Amorpha furticosa) were founded. According to analysis results form place of origin, Europe covered 26 taxa (37.1%), North America covered 23 taxa (32.8%). Naturalized degree 3 plants, as common but not abundant, founded as 24 taxa (35.0%) were hold most highly ratio, naturalized degree 1 plants founded as 3 taxa (4.0%) were hold lowest. Introduction period 1 covered 31 taxa (44.3%) have had highest score and period 2 covered 11 taxa (15.7%) have had lowest scores. In addition, the urbanization index based on 271 taxa was 25.8% and 2 taxa (Solanum carolinense, Ambrosia artemisiaefolia) is growing in the Gwangyang Steel Works by ecosystem disturbing wild plants. Meanwhile, Ambrosia artemisiaefolia have confirmed into several tens~hundred in the Gwangyang Steel Works were damage the human body of plants develop an allergy to pollen. Solanium carolinense have composed several large communities about $10m{\times}10m$ ($100m^2$) and hold a dominant position, so management plan of the sequel of monitoring them might be required.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.3
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• pp.33-48
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• 2009

A palustrine wetland is a type of a wetland that prevails in Korea as well as an ecosystem that provides various ecological functions and has affluent biodiversity. This study was conducted to understand the characteristics of vegetation in a palustrine wetland by analyzing a life form and naturalized plants, in order to present the maintenance and utilization plan of a small wetland. A total of 249 taxa including 76 families, 188 generics, 209 species, 38 varieties and 2 forma were found at six investigated wetlands. As a result of the appearance ratio analysis, Therophytes (37.8%) with 94 taxa and Hemicryptophytes (31.3%) with 78 taxa were in order of life form, and Gramineae (14.1 %) with 35 taxa and Compositae (11.2 %) with 28 taxa were in order of family level. These were deemed representative vegetation in a palustrine wetland. Equosetum arvense, Phragmites communis, Commelina communis, Persicaria thunbergii, Arenaria serpyllifolia, Stellaria media, Erigeron annuus, Erigeron canadensis and Artemisia princeps var, orientalis were found continuously for a period of investigation in all sites. Equosetum arvense, Phragmites communis and Persicaria thunbergii were species with high appearance frequency. Especially, Persicaria thunbergii was construed high in a cover ratio in May as it develop first among Hydrophytes and form a canopy sooner than anything else. We found that a degree of naturalization and an urbanization index appear comparatively high in Yeongok-ri, Cheonan, Gangjang-ri, Asan and Yodang-ri, Hwasung, which is construed due to artificial interference, such as fanning, fishing, swimming and green-tour program. These results would be used to utilize in restoring a deserted and damaged wetland and to provide fundamental data in creating a wetland as follows.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.2
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• pp.13-30
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• 2019

The purpose of this study was to investigate changes in vegetation and flora after five years through field surveys data with the Han Gang Watershed Management Committee (2013) data in order to observe natural vegetation changes in the riparian zone of Han River watershed. As a result, the flora of the riparian zone in 2012 were listed total 231 taxa, 66 families, 158 genus, 207 species, 23 varieties, and 1 forms, and in 2017, a total 247 taxa, 74 families, 174 genus, 218 species, 27 varieties, and 2 forms were identified. The number of rare plants decreased from 4 taxa in 2012 to 2 taxa in total in 2017, and the number of endemic plants increased from 1 taxa to 3 taxa. The number of specific plants by floral region decreased from 21 taxa (9.1% of all 231 taxa of flora) in 2012 to 16 taxa (6.5% of all 247 taxa of flora) in 2017. The total number of naturalized plants is analyzed to increase from 35 taxa, a naturalization rate of 15.15% (all 231 taxa of flora) and urbanization index of 11.2% (all 312 taxa of naturalized plants) in 2012 to 44 taxa a naturalization rate of 17.8% (all 231 taxa of flora) and urbanization index of 14.1%(all 312 taxa of naturalized plants) in 2017. The ecosystem disturbance species showed an increase in both number of species and cover degree grades, indicating that the riparian zone changed in a negative direction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.915-922
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• 2008

Impervious surface is an important index for the estimation of urbanization and the assessment of environmental change. In addition, impervious surface influences on short-term rainfall-runoff model during rainy season in hydrology. Recently, the necessity of impervious surface estimation is increased because the effect of impervious surface is increased by rapid urbanization. In this study, impervious surface estimation is performed by using remote sensing image such as Landsat-7 ETM+image with $30m{\times}30m$ spatial resolution and satellite image with $1m{\times}1m$ spatial resolution based on Jungnangcheon basin. A tasseled cap transformation and NDVI(normalized difference vegetation index) transformation are applied to Landsat-7 ETM+ image to collect various predict variables. Moreover, the training data sets are collected by overlaying between Landsat-7 ETM+ image and satellite image, and CART(classification and regression tree) is applied to the training data sets. As a result, impervious surface prediction model is consisted and the impervious surface map is generated for Jungnangcheon basin.

• Journal of Environmental Impact Assessment
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• v.22 no.2
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• pp.147-156
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• 2013

Myanmar(Burma) has been preserved valuable environmental resources because of its political isolation. But recently, Myanmar has moved a capital city(Naypyidaw) at central forest area and it has been urbanized radically since 2005. In this paper, we built multi-temporal land cover map from Landsat images of 1970s to 2012 with ENVI 4.5 software. For a broad approach, administrative district Yamethin which includes Naypyidaw is classified into 3 classes and with only Naypyidaw region is classified with 4-5 classes to analyse specific changes. And with forest cover extracted by Object Oriented Classification, we evaluated forest fragmentation before and after the development using Patch Analyst(FRAGSTATs 3.3) at Yamethin area. For Yamethin area, there were significant forest cover change, 51% in 1999 to 48% in 2012, and for Naypyidaw area, 67% in 1999 to 57% in 2012 respectively. Also landscape indices resulted from Patch Analyst concluded that the total edge, edge density and mean shaped index of forest patches increased and total core area is decreased. It is attributed from land cover change with urbanization and agricultural land expansion.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.536-536
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• 2015

지난 반세기에 걸쳐 우리나라 대도시에서는 집중호우로 인한 피해가 증가했다. 강우 특성의 변화를 야기하는 요인으로 여러 가지가 있겠으나, 그 중 도시화의 영향에 주목할 필요가 있다. 도시화는 여러 가지 기상특성의 변화를 야기하는 것으로 알려져 있으며, 수문순환에도 영향을 줄 수 있다. 우리나라 도시는 한국전쟁 이후 급격히 성장했으므로, 도시화의 영향이 같은 시기 우리나라 도시에서 증가한 집중호우 빈도와 관련이 있을 개연성이 있다. 이에 본 연구에서는 도시화 진행과 강우특성 변화와의 상관관계를 분석하여 이러한 가설을 뒷받침할 기초 증거를 수집하였다. 구체적으로 12개 지점, 37년간(1975~2011)의 일 강우 자료를 이용하여 총 강우량, 연 최대 강우량, 연 중 강우일수, 10/30/50/80 mm 초과강우일수의 경향성을 파악하였고, 도시화의 진행 정도를 분석하기 위해서 시가화면적비, 인구를 고려한 도시화지수(urbanization index, UI)를 구축하여 같은 방법으로 경향성을 파악하였다. 강우특성의 경향을 살펴본 결과, 대상 지역의 총 강우량과 큰 호우사상은 해마다 증가하는 추세로 확인되었으며, 나머지 강우 특성에는 큰 경향성이 없는 것으로 확인되었다. 최종적으로 UI의 변화와 강우특성 경향 간의 상관관계를 비교한 결과, UI는 50 mm 이상 강우일수, 80 mm 이상 강우일수, 총 강우량과 높은 상관관계를 보이는 것으로 확인되었다. 결론적으로, 도시화가 진행되는 정도에 따라 큰 호우 사상의 발생빈도가 크게 달라진다고 볼 수 있다. 따라서, 향후 도시화의 진행에 따른 집중호우의 피해를 예방하기 위해서는 해당 분야의 지속적인 연구가 필요하다고 판단된다.

• Journal of Climate Change Research
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• v.7 no.3
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• pp.357-371
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• 2016

Buildings in the city acts as a cause of distorted wind direction, wind speed, causing the stagnation of the air flow. In the recent trend of climate change can not but consider the temperature rise of the urbanization. This study was aimed to analyze the thermal comfort of planetary boundary layer in different artificial constructions areas which has a direct impact on urban climate, and estimating the warming phenomena. Envi-met model was used to consider the urban structure associated with urban growth in order to precisely determine the impact of the building on the city weather condition. The analyzed values of thermal comfort index were temperature, wind speed, horizontal and vertical turbulent diffusivity. In particular, analysis of the PPD(Predicted Percentage of Dissatisfied) represents the human thermal comfort. In this study, by adjusting the arrangement and proportion of the top floor building in the urban it was found that the inflow of the fresh air and cooling can be derived low PPD. Vertical heat flux amount of the city caused by climate change was a factor to form a high potential temperature in the city and the accumulation of cold air does not appear near the surface. Based on this, to make the city effectively respond to climate change may require a long-term restructuring of urban spatial structure and density management.

• Journal of the Korean Regional Science Association
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• v.39 no.3
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• pp.3-12
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• 2023

The issue to be discussed is set as the relationship between urban fragmentation and urban heat phenomena. The fragmentation is recognized as a negative form that commonly occurs in the process of urbanization. The purpose of this study is to examine the relationship between urbanization entropy and heat phenomenon by looking at the five major cities in Korea. The employed methods are InVEST Urban Cooling Model and MSPA (Morphological Spatial Pattern Analysis) by using the meteological data for the July 2018. The major results are as follows; First, a low rank correlation(rho=-0.3) is found in the relation between entropy and Cooling Capacity Index (CCi). Second, a very high level of rank correlation is observed between entropy and Average Temperature(℃)(rho=0.9). The implications are that 1) a city with a large degree of sprawling development can have a negative effect on urban heat phenomena; 2) the composition of land use including dispersion and concentration in non-urbanized areas, which has the characteristics of open space, can affect the urban thermal environment. Due to the limited number of case studies, it is appropriate to understand that a possibility, not generalization, is observed between entropy and heat phenomena in urbanized areas.