• Journal of Wetlands Research
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• v.25 no.4
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• pp.353-365
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• 2023

The effects of climate change on green infrastructure and environmental media remain uncertain and context-specific despite numerous climate projections globally. In this study, the extreme weather conditions in seven major cities in South Korea were characterized through statistical analysis of 20-year daily meteorological data extracted fro m the Korea Meteorological Administration (KMA). Additionally, the impacts of extreme weather on Nature-based Solutions (NbS) were determined through a comprehensive review. The results of the statistical analysis and comprehensive review revealed the studied cities are potentially vulnerable to varying extreme weather conditions, depending on geographic location, surface imperviousness, and local weather patterns. Temperature extremes were seen as potential threats to the resilience of NbS in Seoul, as both the highest maximum and lowest minimum temperatures were observed in the mentioned city. Moreover, extreme values for precipitation and maximum wind speed were observed in cities from the southern part of South Korea, particularly Busan, Ulsan, and Jeju. It was also found that extremely low temperatures induce the most impact on the resilience of NbS and environmental media. Extremely cold conditions were identified to reduce the pollutant removal efficiency of biochar, sand, gravel, and woodchip, as well as the nutrient uptake capabilities of constructed wetlands (CWs). In response to the negative impacts of extreme weather on the effectiveness of NbS, several adaptation strategies, such as the addition of shading and insulation systems, were also identified in this study. The results of this study are seen as beneficial to improving the resilience of NbS in South Korea and other locations with similar climate characteristics.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.2
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• pp.92-104
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• 2015

In order to analyze the impacts of climate change, a time and space integrated model was developed in this study using system dynamics and GIS. The model built was used to carry out a simulation on the inundation impact on A-gu of Busan Metropolitan city resulting from the sea level rise scenario of IPCC and storm surge, which is the worst case. Through this, the flooded area and population until 2100 were predicted. Also, the result and significance of each alternative was reviewed improving the model by establishing alternative scenarios of protection, accommodation and retreat as plans of reaction to sea level rise. The combination of system dynamics and GIS has advantages of how the diverse variables change until the target year can be traced and, accordingly, not only the results but also the processes of spatial change can be examined by calculating the value of change process at each time step. The synergy of this model presumed to be a foothold for solving problems which are becoming difficult to predict due to increase in uncertainty and complexity such as the support for decision making for urban resilience to natural disasters.

• Journal of the Korean association of regional geographers
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• v.21 no.4
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• pp.751-763
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• 2015

Both the selection of indicators and weights for them are critical issues in the vulnerability assessment. This study is to assess the air pollution vulnerability focused on ozone for 249 local jurisdictions using weights calculated by the entropy methodology and then examine the applicability of the methodology. We selected indicators for air pollution vulnerability assessment and standardized them. Subsequently, we calculated weights of each indicator using the entropy method and then integrated them into the vulnerability index. The exposure indicators consider meteorological and air pollution factors and the sensitivity of the local jurisdiction include variables on vulnerable areas and environments. The adaptive capacity contains socio-economic characteristics, health care capacities and air pollution managemental factors. The results show that Hwaseong-si, Gwangjin-gu, Gimpo-si, Gwangju-si, Gunpo-si are among the highest vulnerabilities based on the simple aggregation of indicators. And vulnerability-resilience (VRI) aggregation results indicates the similar spatial pattern with the simple aggregation outcomes. This article extends current climate change vulnerability assessment studies by adopting the entropy method to evaluate relative usefulness of data. In addition, the results can be used for developing customized adaptation policies for each jurisdiction reflecting vulnerable aspects.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.6
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• pp.21-32
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• 2023

The Environmental Impact Assessment (EIA) plays a pivotal role in predicting the potential environmental impacts of proposed developments and planning appropriate mitigation measures to minimize effects on species. However, as concerns over biodiversity loss rise, there's ongoing debate about the efficacy of these mitigation plans. In this study, we utilized data from EIAs and post-environmental impact surveys to understand the trends in biodiversity during construction and operation phases. By examining 30 urban development projects, we categorized species richness indices of mammals, birds, amphibians, and reptiles into pre-construction, during construction, and post-construction operational stages. The biodiversity trends were analyzed based on the rate of change in these indices. The results revealed three distinct biodiversity change patterns: (A) An initial increase in biodiversity indices post-development, followed by a gradual decline over time; (B) a sustained increase in biodiversity as a result of mitigation measures; and (C) a continuous decline in biodiversity post-development. Furthermore, all species exhibited a higher rate of biodiversity decline during the construction phase compared to the operational phase, with mammals showing the most significant rate of change. Notably, the biodiversity change rate during operation was generally lower than during construction. In particular, mammals seemed to be most influenced by mitigation measures, displaying the smallest rate of change. This study provides empirical evidence on the efficacy of mitigation measures and deliberates on ways to enhance their effectiveness in minimizing the adverse impacts of urban development on biodiversity. These findings can serve as foundational data for addressing terrestrial biodiversity reduction.

• World Technopolis Review
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• v.8 no.1
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• pp.59-70
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• 2019

Where is a better place to live? In the coming era, this should be more than simply a livable place. It should be an adaptable place that has a flexible system adaptable to any new situation in terms of diversity. Customization and real-time operation are needed in order to realize this technologically. We expect a smart city to have a flexible system that applies technologies of self-monitoring and self-response, thereby being a promising city model towards being a better place to live. Energy demand and supply is a crucial issue concerning our expectations for the flexible system of a smart city because it is indispensable to comfortable living, especially city living. Although it may seem that energy diversification, such as the energy mix of a country, is a matter of overriding concern, the central point is the scale of place to build grids for realizing sustainable urban energy systems. A traditional hard energy path supported by huge centralized energy systems based on fossil and nuclear fuels on a national scale has already faced difficult problems, particularly in terms of energy flexibility/resilience. On the other hand, an alternative soft energy path consisting of small diversified energy systems based on renewable energy sources on a local scale has limitations regarding stability, variability, and supply potential despite the relatively light economic/technological burden that must be assumed to realize it. As another alternative, we can adopt a holonic path incorporating an alternative soft energy path with a traditional hard energy path complimentarily based on load management. This has a high affinity with the flexible system of a smart city. At a system level, the purpose of all of the paths mentioned above is not energy itself but the service it provides. If the expected energy service is fixed, the conclusive factor in choosing a more appropriate system is accessibility to the energy service. Accessibility refers to reliability and affordability; the former encompasses the level of energy self-sufficiency, and the latter encompasses the extent of energy saving. From this point of view, it seems that the small diversified energy systems of a soft energy path have a clear advantage over the huge centralized energy systems of a hard energy path. However, some insuperable limitations still remain, so it is reasonable to consider both energy systems continuing to coexist in a multiplexing energy system employing a holonic path to create and maintain reliable and affordable access to energy services that cover households'/enterprises' basic energy needs. If this is embodied in a smart city concept, this is nothing else but smart energy inclusion. In Japan, following the Fukushima nuclear accident in 2011, a trend towards small diversified energy systems of a soft energy path intensified in order to realize a nuclear-free society. As a result, the Government of Japan proclaimed in its Fifth Strategic Energy Plan that renewable energy must be the main source of power in Japan by 2050. Accordingly, Sony vowed that all the energy it uses would come from renewable sources by 2040. In this situation, it is expected that smart energy inclusion will be achieved by the Japanese version of a smart grid based on the concept of a minimum cost scheme and demand response.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.265-270
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• 2022

The purpose of this study is to derive the damage weak part of the elastic rail fastening system for concrete tracks (System 300-1). In the concrete tracks, the elastic rail fastening system sticks the rail and the sleeper and reacts all the time when the train is running. Among the components of the rail fastening system, the resilience pad and tension clamp were fatigue members and were constantly deformed in response to compressive and uplift forces. In this study, the residual deformation characteristics of the tension clamp according to the period of use were analyzed using by specimens taken on site in the same section for 6, 11, and 16 years on the serviced urban transit. In addition, the damage mechanisms for each component were derived based on finite element analysis. As a result of the numerical analysis, the stress (strain) of each part of the tension clamp according to the external force from the applied clamping force was analyzed to derive the damaged weak part of the tension clamp.

• Ecology and Resilient Infrastructure
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• v.9 no.4
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• pp.207-217
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• 2022

The purpose of this study was to understand and develop various environmental designs to play a key roles in urban design, so that public green spaces remain vital with future changes. Variability in space, ecology, and society were analyzed based on research of variable environmental spaces in 11 selected studies conducted locally and abroad since the 2010s. Moreover, landscape characteristics, design methods, and design strategies were analyzed accordingly for each case. The results of the study showed that variability in landscapes provided various possibilities for spatial change and satisfied people's functional needs for spatial use. In addition, variable environmental design greatly compensated for the defects by solving the issues associated with fixed landscapes by increasing the flexibility of use and adaptability to the environment. This study showed that variable design is applicable to public green spaces; environmental stress; and variability in architecture, the environment, and landscaping, and it contributes to enhancing the sustainability and resilience of the environment.

• International Journal of High-Rise Buildings
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• v.12 no.1
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• pp.93-105
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• 2023

Seismic isolation and vibration control techniques have been developed and put into practical use by challenging researchers and engineers worldwide since the latter half of the 20th century, and after more than 40 years, they are now used in thousands of buildings, private residences, highways in many seismic areas in the world. Seismic isolation and vibration control structures can keep the structures undamaged even in a major earthquake and realize continuous occupancy. This performance has come to be recognized not only by engineers but also by ordinary people, becoming indispensable for the formation of a resilient society. However, the dynamic characteristics of seismically isolated bearings, the key elements, are highly dependent on the size effect and rate-of-loading, especially under extreme loading conditions. Therefore, confirming the actual properties and performance of these bearings with full-scale specimens under prescribed dynamic loading protocols is essential. The number of testing facilities with such capacity is still limited and even though the existing labs in the US, China, Taiwan, Italy, etc. are conducting these tests, their dynamic loading test setups are subjected to friction generated by the large vertical loads and inertial force of the heavy table which affect the accuracy of measured forces. To solve this problem, the authors have proposed a direct reaction force measuring system that can eliminate the effects of friction and inertia forces, and a seismic isolation testing facility with the proposed system (E-isolation) will be completed on March 2023 in Japan. This test facility is designed to conduct not only dynamic loading tests of seismic isolation bearings and dampers but also to perform hybrid simulations of seismically isolated structures. In this paper, design details and the realization of this system into an actual dynamic testing facility are presented and the outcomes are discussed.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.21-21
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• 2023

현재 구축되어있는 방재시설의 능력은 기후위기로 인해 수용가능한 극한강우량의 범위를 넘어서고 있어 대형화된 홍수로 인한 피해가 꾸준히 발생하고 있다. 이로 인해 잠재적 홍수로 인한 도시회복도 관리와 홍수로 수반되는 피해에 대한 복구의 중요도가 높아지고 있다. 회복도는 도시의 재해 취약성, 저항, 적응, 복구, 완화에 대한 능력을 포괄하는 개념으로써 최근 주목받고 있는 개념이지만 대부분의 연구는 주로 시설에 대한 회복도 평가가 이루어지고 있다 (Sen et al.,2021). 또한 재해 후 도시복구에 관한 연구는 다수 존재하지만 복구에 따른 지역의 회복도 변화와 라이프라인과 같은 주요 시설의 복구에 따른 회복도 차이를 고려한 연구는 미비한 실정이다. 따라서 본 연구에서는 도시침수 발생 후 라이프라인을 고려한 도시복구 우선순위 산정모델을 개발하고 재해관리의 효율성 향상측면에서 도시의 기능적 회복도를 평가하였다. 이를 위해 라이프라인 중 도로 복구결과의 평가를 위하여 리스크 매트릭스 기법을 이용한 도로위험도평가를 수행하였으며 도시의 회복도를 측정하였다. 회복도를 크게 홍수로부터 도시가 받은 영향과 재해복구역량으로 구성하였으며 정량적인 평가를 위해 각각 손상함수와 재해재난목적예비비를 활용하여 산정하였다. 이후 복구우선순위를 산정하였으며 복구와 도시회복도와의 관계를 분석하기 위하여 재해연보 자료를 기초로 회귀분석을 통해 복구비용을 추정하였다 (유순영 등.,2014). 시범지역에 적용한 결과 시설 및 도로 복구에 따른 도시영향의 변화보다 복구비사용으로 인한 재해복구역량의 변화가 더욱 크다는 것을 확인하였다. 이는 재해재난목적예비비의 중요성이 크다는 것을 의미하며 향후 추가적인 인문학적, 법제적 요소가 회복도에 미치는 영향을 연구한다면 도시회복도 향상 및 도시복구에 관한 정책적 의사결정에 큰 도움이 될 것이다.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.1
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• pp.76-87
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• 2019

The purpose of this study was to evaluate the performance of and to derive future maintenance-management measures of the constructed alternative habitat for the Kaloula borealis at the University of Seoul, examining the period between 2015-2017. The research was constructed in 2014 and in a $191m^2$ area. The performance evaluation was divided into maintaining the habitat of the target species, maintaining the population and reproduction rates of the target species, maintaining the habitat of the wild species, the resilience of natural ecosystems, and the harmony with the surrounding environment. In terms of maintaining the habitat of the target species, soil collected from the existing habitat of the Kaloula borealis and was the depth was increased to 30cm in the alternative habitat. An artificial water supply was required every year during the supporting the spawning and hatching of other amphibians along with the Kaloula borealis. The sources of water of the alternative habitat were both rain and tap water, as it cannot be maintained naturally. Additionally, the Kaloula borealis thrived because it inhabited the research site and the average temperature was $26.2^{\circ}C$ from April-June, which is when the Kaloula borealis spawns. In terms of maintaining the population and reproduction rates of the Kaloula borealis, they were evaluated to have stable rates of reproduction. In terms of maintaining the habitat of the wild species, studies on vegetation and the structure of the characteristics of prey or predators will be needed. Also, alien species, such as Humulus japonicus and Bidens frondosa needed to be removed to maintain the wetland ecosystem of the wild species. In the assessment of the resilience of the natural ecosystems, the mud was monitored, noting the changes in the depth of water, with steps taken to reduce the leakage of water. The mud collected from the Haneul Pond wetland, which is located around the research site was piled up. Also, partial mowing management and the inducement of a natural vegetation colony was required for vegetation management. It was also necessary to create porous spaces, such as old trees and tree branches to create a habitat with hiding places and feeding and spawning places for small organisms. In terms of the harmony with the surrounding environment, the following threat factors needed to be managed: amphibian roadkill by vehicles and pedestrians and artificial draining due to nearby user access. Based on the monitoring results, alternative habitat management measures presented the promoting various waterside structures, in which amphibians can spawn and hide in, managing the water environment consistently, managing the vegetation, focused on the habitat of the wild species, and managing the surrounding environment for the habitat. The creation of an alternative habitat should be managed through monitoring, reflecting the characteristics of the changes in the site. Also continuing efforts are also needed to improve the habitat of the target species.