• 한국멀티미디어학회논문지
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• 제17권4호
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• pp.478-489
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• 2014

Recently, flood damage by frequent localized downpours in cities are on the increase on account of abnormal climate phenomena and growth of impermeable area by urbanization. In this study, we are focused on flooding on roads which is the basis of all means of transportation. To calculate real-time accumulated rainfall on a road link, we use the Coefficient of Correlation Weighting method (CCW) which is one of the revised methods of missing rainfall as we consider a road link as a unobserved rainfall site. CCW and real-time accumulated rainfall entered through the Internet are used to estimate the real-time rainfall on a road link. Together with the real-time accumulated rainfall, flooding history, rainfall range causing flooding of a road link and frequency probability precipitation for road design are used as factors to determine the Flood Risk Index on roads. We simulated two cases in the past, July, 7th, 2009 and July, 15th, 2012 in Busan. As a result, all of road links included in the actual flooded roads at that time got the high level of flood risk index.

• 한국환경복원기술학회지
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• 제18권6호
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• pp.15-25
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• 2015

The growth of impermeable layers in the city center due to today's urban development is emerging as a major cause of urban heat island effects as well as recurring inland flood damages. In order to cope with such disasters caused by climatic changes, an artificial ground afforestation system is suggested as a fundamental solution that addresses both water environment and heat environment. For the afforestation system to replace the current disaster prevention facilities, quantitative performance verification through related numerical analysis models and actual survey monitoring is necessary. Therefore, this study seeks to propose the performance predication method for the heat environment of the afforestation system by looking into correlations between measurements by physical vegetation indicators such as LAI and FVC and forecasts from FASST, a vegetation canopy model used by US Corps of Engineers.

• Ocean Systems Engineering
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• 제1권4호
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• pp.337-353
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• 2011

In the present study, an offshore platform having large partial porous cylindrical members, which are composed of permeable and impermeable cylinders, is suggested. In order to calculate the wave force on large partial porous cylindrical members, the fluid domain is divided into three regions: a single exterior region, N inner regions and N beneath regions, and the scattering wave in each fluid region is expressed by an Eigen-function expansion method. Applying Darcy's law to the porous boundary condition, the effect of porosity is simplified. Wave excitation forces and wave run up on the structures are presented for various wave conditions. For the idealized three-dimensional platform having large partial porous cylindrical members, the dynamic response evaluations of the platform due to wave forces are carried out through the modal analysis. In order to examine the effects of soil-structure interaction, the substructure method is also applied. The displacement and bending stress at the selective nodal points of the structure are computed using various input parameters, such as the shear-wave velocity of soil, the wave height and the wave period. Applying the Monte Carlo Simulation (MCS) method, the reliability evaluations at critical structure members, which contained uncertainties caused by dynamic forces and structural properties, are examined by the reliability index with the results obtained from MCS.

• 대한원격탐사학회지
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• 제38권1호
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• pp.127-137
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• 2022

Urban Heat Island (UHI) effect has been widely studied as a global concern of the 21st century. Heat generation from urban built-up structures and anthropogenic heat sources are the main factors to create UHIs. Unfortunately, both factors are expanding rapidly in Lahore and accelerating UHI effects. The effects of UHI are expanding with the expansion of impermeable surfaces towards urban green areas. Therefore, this study was arranged to analyze the role of urban cooling intensity in reducing urban heat island effects. For this purpose, 15 parks were selected to analyze their effects on the land surface temperature (LST) of Lahore. The study obtained two images of Landsat-8 based on seasons: the first of June-2018 for summer and the second of November-2018 for winter. The LST of the study area was calculated using the radiative transfer equation (RTE) method. The results show that the theme parks have the largest cooling effect while the linear parks have the lowest. The mean park LST and PCI of the samples are also positively correlated with the fractional vegetation cover (FVC) and normalized difference water index (NDWI). So, it is concluded that urban parks play a positive role in reducing and mitigating LST and UHI effects. Therefore, it is suggested that the increase of vegetation cover should be used to develop impervious surfaces and sustainable landscape planning.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년도 추계학술발표대회 논문집
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• pp.100-103
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• 2009

The impermeable area on the surface of city has been increased as buildings and artificial landcover have continually been increased. Urban development has gradually decreased the green zone in downtown and alienated the city from the natural environment on outskirt area devastating the natural eco system. There arise the environmental problems peculiar to city including urban heat island phenomenon, urban flood, air pollution and urban desertification. As one of urban plans to solve such problems, green roof system is attracting attentions. The purpose of this study was to investigate the heat reduction effect according to the development of green roof system and to quantify the heat reduction effect by analyzing through simulation the heat environment before and after green roof system. For thermal environment analysis, Thermo-Render 3.0 was used that was developed by Tokyo Industrial College to simulate. The simulation showed that the heat island index before and after the development of tree-planting on rooftop changed maximum $0.86^{\circ}C$ and the surface temperature changed about $20^{\circ}C$. Only with lawn planting, heat reduction effect was great and it means that the green roof system in low-management-light-weight type is enough to see effect. The simulation identified that only lawn planting for green rooftop brought such difference and could lower the heat island index at a narrow area. It is judged that application of green roof system to wider areas might relieve urban heat island phenomenon positively.

• 한국환경생태학회지
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• 제18권1호
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• pp.53-60
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• 2004

아파트단지 내부녹지가 온도변화에 미치는 영향을 파악하고자 서울시 서초구, 강남구, 송파구 등 한강 이남지역에 위치한 아파트단지중 36개 지역을 대상으로 연구를 수행하였다. 아파트단지 내부온도는 Landsat ETM＋영상 2scene을 분석하여 추정하였으며 온도변화 영 향요인으로는 토양피복유형과 건물밀도, 식생활력도로 구분하였다. 토양피복유형과 아파트단지내 온도와의 상관관계 분석결과 녹지율은 음(－)의 상관관계를, 불투수포장율은 양(＋)의 상관관계를 보였으며 건폐율은 유의성이 인정되지 않았다. 투수포장지를 녹지면적과 불투수포장면적에 각각 합산한 값과 온도값의 상관관계 분석결과 투수포장면적을 불투수포장면적에 합산하여 산출한 상관계수보다 녹지면적에 합산하는 것이 상관계수가 보다 높게 나타나 투수포장지역도 녹지지역과 함께 도시온도를 낮추는 요소로 작용하는 것으로 판단되었다. 건물밀도의 요소로 선정한 용적율은 온도값과 유의성이 없었으며 NDVl는 값이 높을수록 온도가 낮았다. 아파트단지내 온도분포모형 구축을 위해 투수＋녹지율, 녹지율, 건폐율, NDVI값을 독립변수로, 대상지온도를 종속변수로 한 회귀분석 결과 두 시기 영상 모두 독립변수 중 투수＋녹지율만이 회귀식에 채택되었으며 회귀식의 수정 결정 계수($R^2$)는 각각 41.4(2000년 9월)와 40.4(2001년 6월)이었다.

• 한국조경학회지
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• 제48권5호
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• pp.16-27
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• 2020

본 연구는 서울시 도심 하천 중 국가하천인 중랑천을 대상으로 보전지역 설정 프로그램인 Marxan with zones 프로그램을 기반으로 한 하천 내 보전지역 설정 및 생태적 관리방안을 제시하였다. Marxan with zones 프로그램 적용은 유역권(planning unit) 설정, 맵핑지표(mapping index) 적용, 반복적인 분석을 위한 수치보정, 분석을 통한 시나리오 별 최적안 작성, 시나리오 별 민감도 분석, 시나리오 중 최적안 검토 및 선정 단계로 진행하였다. 중랑천 내 보전지역 설정 결과, 기존에 보전지역으로 지정 및 관리하고 있는 중랑천 상류 야생생물보호구역을 포함한 다수의 유역권과 중랑천 하류의 철새보호구역을 포함한 유역권이 핵심보전지역으로 설정되었다. 상류는 중랑천을 중심으로 수락산과 도봉산 등 산림이 인접하여 다수의 야생조류가 관찰되었다. 하류는 한강 합수부, 청계천 합수부 등 하천생태계가 인접하여 하천을 따라 이동하는 철새 도래지이다. 따라서 중랑천 상류와 하류는 유역권 내 도봉산, 수락산, 응봉산 등 산림생태계, 도심 내 녹지, 청계천 합수부, 한강 합수부 등 다양한 생태계와 연결되어 있어 보전지역 설정에 영향을 주었다. 본 연구는 보전지역 검증 시 Marxan with zones 프로그램을 통한 기존 보전지역 설정 및 평가를 검증하였고, 프로그램을 통해 핵심보전지역으로 도출된 유역권을 생태적으로 관리하기 위해 하천 내 관리방안과 유역권 관리방안으로 구분하여 제시하였다.

• 한국환경복원기술학회지
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• 제23권5호
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• pp.1-14
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• 2020

In order to improve the urban thermal environment, efforts are being made to increase green areas in cities that include park construction, planting, and green roofing. Among these efforts, urban parks play an important role not only in improving the urban thermal environment, but also in terms of ecosystem services (serving as resting places for citizens, providing cleaner air quality, reducing noise, etc.). Therefore, the purpose of this study is to suggest planning and management guidelines for urban parks that are effective in improving the thermal environment, by analyzing the urban surface temperature reduction performance of urban parks. To do this, first, land surface temperature was calculated by using Landsat 8 images. Second, the PCI (Park Cool Island) index was calculated to identify the temperature reduction performance of urban parks. Third, the characteristics of parks (area, shape, vegetation) and the surrounding spatial characteristics (land cover, building-related variables, etc.) were identified. Finally, the relationship between the PCI indices (PCI scale, PCI effect, PCI intensity) and the characteristics of the parks and their surroundings were analyzed. The results revealed that the parks consisting of a larger area, simple shape, and higher tree coverage ratio had increased PCI performance, and were advantageous for improving the urban thermal environment. Meanwhile, PCI performance was found to have decreased in areas with a higher impermeable area ratio and building coverage ratio. The outcomes of this study can be used to identify priority areas for planning and management of urban parks and can also be utilized as planning and management guidelines for improving urban thermal environment.

• 국토계획
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• 제53권7호
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• pp.109-126
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• 2018

The purpose of this study is to identify the spatial types for thermal environment improvement considering heat flux and its spatial context through empirical orthodox formulas. First, k-means clustering was used to classify values of three kinds of heat flux - latent, sensible and storage heat. Next, from the k-means clustering, we defined a type of thermal environment (type LHL) where improvement is needed for more comfortable and pleasant thermal environment in the city, among the eight types. Lastly, we compared and analyzed the characteristics of each classified thermal environmental types based on land cover types. From the study, we found that the ratio of impervious surfaces, roads, and buildings of the type LHL is higher than those of the type HLH (relatively thermal comfort environment). In order to improve the thermal environment, the following contents are proposed to urban planners and designers depending on the results of the study. a) Increase the green zone rate by 10% to reduce sensible heat; b) Reduce the percentage of impermeable surfaces and roads by 10% ; c) Latent heat increases when water and green spaces are expanded. This study will help to establish a minimum criterion for a land cover rate for the improvement of the urban thermal environment and a standard index for the thermal environmental improvement can be derived.

• 한국환경복원기술학회지
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• 제23권6호
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• pp.167-185
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• 2020

The purpose of this study is to prepare a plan for improving the bird habitat environment of Linear Park. To this end, after grasping the status of bird habitats on the Gyeongchun Line Forest Road, a representative linear park in Seoul, the habitat environment was evaluated and the correlation with the bird habitat was analyzed to derive a plan to improve the habitat environment. The results for correlation between diversity of birds and habitat environment were as follows. For the habitat environment inside the park, the order of positive correlation was in the order of park area (0.92), number of insect species (0.87), green area ratio (0.77), average width of linear park (0.74), Biotope area ratio (0.73), Immigration planted species (0.57). Also, for habitat environment outside the park, the bird diversity was influenced in the order of area outside the park (0.88), green area ratio of the park (0.76). Thus, in order to enhance the diversity of birds found in the park, the bird habitat environment inside the park needs to expand the park area, secure insect diversity, enhance green area ratio and ecological area ratio, expand the width of linear park, and lower the impermeable layer. For the bird habitat environment outside the park, wider area, green area ratio, and forest area of the park influenced on better bird habitation while lower ratio of road space and building-to-land ratio influenced on higher bird diversity. It is necessary to create an environment inhabitable for various species of birds and to make a healthy and pleasant city urban system for co-existence of human and living creatures.