• Title/Summary/Keyword: Urban ecosystems

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Urban Thermo-profiles and Community Structure of Quercus mongolica Forests along an Urban-rural Land Use Gradient: Implications for Management and Restoration of Urban Ecosystems

  • Cho, Yong-Chan;Cho, Hyun-Je;Lee, Chang-Seok
    • Journal of Ecology and Environment
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    • v.32 no.3
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    • pp.167-176
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    • 2009
  • Land cover changes associated with urbanization have driven climate change and pollution, which alter properties of ecosystems at local, regional, and continental scales. Thus, the relationships among urban ecological variables such as community composition, structure, health, soil and functioning need to be better understood to restore and improve urban ecosystems. In this study, we discuss urban ecosystem management and research from a futuristic perspective based on analyses of vegetation structure, composition, and successional trends, as well as the chemical properties of soils and the distribution of heat along an urban-rural gradient. Urban thermo-profile analysis using satellite images showed an obvious mitigating effect of vegetation on the Seoul heat island. Community attributes of Quercus mongolica stands reflected the effects of urbanization, such as pronounced increases in disturbance-related and pollution-tolerant species, such as Styrax japonica and Sorbus alnifolia. Retrogressive successional trends were detected in urban sites relative to those in rural sites. Changes in the urban climate and biotic environment have the potential to significantly influence the practice and outcomes of ecological management, restoration and forecasting because of the associated changes in future bio-physical settings. Thus, for management (i.e., creation and restoration) of urban green spaces, forward-thinking perspectives supported by historical information are necessary.

A Study on the Urban Ecosystem Assessment for 31 Cities & Counties around the Capital (수도권 31개 시·군의 도시생태계 현황 평가에 관한 연구)

  • Sung, Hyun-Chan;Hwang, So-Young
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.5
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    • pp.165-176
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    • 2012
  • The objective of this study is to set urban ecosystem assessment indicators, assess the status of the urban ecosystems in 31 cities & counties in the capital region and based on which, to examine an improvement plan to resolve problems and raise quality and quantity of urban ecosystems. The study showed that the ecological base of 31 cities & counties was 48% on average, which indicates that their ecological property is the middle class. Their natural-ecological function was 63% and environmental-control function was 25%, showing that environment-control function was poor. Therefore, going forward, urban ecological base should be further improved. When securing an ecological base, creation techniques should be able to further enhance environmental-control function along with natural-ecological function. Also, additional effort should be made to conserve areas with high ecological value as much as possible and increase vegetation vitality by replacing tree species.

Application of Eco-hydraulics Principles in Rehabilitation of Urban River System

  • Meiyan, Feng;Jung, Kwansue
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.446-446
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    • 2018
  • The urban rivers have unique hydraulic characteristics between natural rivers and artificial canals. These hydraulic characteristics determine the characteristics of urban rivers with small environmental capacity and fragile ecosystems. With the development and utilization of natural resources, the pollutants that have been produced enter the river through different channels, which seriously damages the urban river ecosystem. Therefore, how to restore contaminated water to a normal state and reproduce a natural, self-regulating ecosystem is one of the most concerned issues in recently. Eco-hydraulics is a cross-disciplinary subject of hydraulics biology and ecology. It is closely related to the protection of rivers, wetlands, and ecological self-repair. In this study, The basic principle of eco-hydraulics is concisely described and its approaches to protection and rehabilitation of river are introduced. The conception of establishing gardenesque eco-pond for urban use is suggested. The strategies including changing the hydrodynamic features of rivers, adjusting the breeds and species and constructing the gardenesque eco-pond for improving the exist ing urban rivers are proposed. It provides scientific information and guidance for the restoration of rivers and wetlands by studying the close relationship between river hydraulic characteristics, currents, and rivers and ecosystems.

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Ecological Planning Technique for Considering Biotope Evaluation of Housing Development Districts (택지개발지구에서의 비오톱 평가에 기초한 환경생태계획 기법 연구)

  • Lee, Soo-Dong
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.6 s.119
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    • pp.22-38
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    • 2007
  • Since 1990, urban areas have been expanded rapidly due to the concentration of the population and several development projects including large scale apartment complexes and residential developments. Due to these development projects, the quality and functions of ecosystems have been continuously degraded, regardless of public agencies' efforts introducing development index, guideline, and amendment of law for sustaining the quality of ecosystems. Substantial guideline and content cannot expect the sustainable maintenance of nation's natural resources. Recent improve this situation, ecological planning was introduced, but research data of environments and objective systems were not enough showing the limits. The purposes of this study were to reduce the urban sprawl caused by residential development plans for environment-friendly residential developments, to establish applicable ecological planning, and to suggest the land use plans that reduce adverse effects of developments to nature ecosystem.

A Study on Securing Instream Flow for Restoring Ecosystems and Riverine Aesthetics of a Degraded Urban Stream - Applied to the Mugeo Stream in the Ulsan Metropolitan Area - (하천생태계와 경관복원을 위한 도시소하천의 유지유량확보에 관한 연구 - 울산 무거천을 중심으로 -)

  • Lee, Soo-Sik
    • Journal of Environmental Science International
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    • v.16 no.5
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    • pp.649-655
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    • 2007
  • This study was focused on estimating instream flow, and its optimal alternative for securing the required total amount of instream flow was also researched in order to restore ecosystems and riverine aesthetics of the Mugeo Stream. the first tributary of the Taewha River flowing through the center of Ulsan. In this study the hydraulic and hydrologic conditions and water quality were investigated at specific channel reaches and representative stations of the Mugeo Stream to determine a proper estimate of instream flow. And riverine functions, such as the minimum flow, water duality conservation, fish habitat, and recreation, were considered to restore the environmental functions of the stream, As a result, the total amount of $11,500m^3/day$ was set as the target instream flow for the Mugeo Stream. It was chosen as the optimal alternative for securing the total external supply of $10,000m^3/day$ which have to be transfered from the riverbed flow diverted through the Taewha Main river at upstream of Samho bridge. The water duality throughout the Mugeo Stream channels will be improved considerably to 3-4 mg/l of BOD standard if the target instream flow is supplied and sewage is intercepted by the sanitary sewage system.

Investigation on the effects of microbial community presence and survival to the water quality performance of urban stormwater nature-based solutions

  • Geronimo, Franz Kevin;Guerra, Heidi;Jeon, Minsu;Reyes, Nash jett;Kim, Lee-Hyung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.139-139
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    • 2022
  • Nature-based solutions (NBS) involved conservation or rehabilitation of natural ecosystems or the creation of natural processes in modified or artificial ecosystems to mimic natural processes for the improved management of water (UN-Water, 2018). This study investigated the relationship between microbial presence and survival to the pollutant treatment performance of seven different stormwater NBS managing urban stormwater runoff. In this study, seven different stormwater nature-based solution (NBS) was investigated to identify the relationship of microbial community to the pollutant removal performance of stormwater NBS. Based on this study, Proteobacteria was found to be the most dominant microorganism for all stormwater NBS and IS followed by Acidobacteria and Actinobacteria. Acidobacteria, Actinobacteria, Chloroflexi, Gemmatimonadetes, WS3, and AF234118_p were found to have high positive correlation to most pollutant removal efficiency of different stormwater NBS (r-value: 0.62 to 0.68). Using Proteobacteria and Acidobacteria count in stormwater NBS, equations predicting pollutant removal performance were also developed and may be used in minimizing the cost for stormevent monitoring to identify the pollutant removal performance of stormwater NBS.

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Green network analysis in coastal cities using least-cost path analysis: a study of Jakarta, Indonesia

  • Kim, Jae-Eun
    • Journal of Ecology and Environment
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    • v.35 no.2
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    • pp.141-147
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    • 2012
  • The rapid urbanization in developing countries is accelerating both the depletion and fragmentation of urban green space, despite the known positive effects of green spaces on the environmental conditions in cities and the quality of life of residents. Consequently, there is a need for practical tools that can support the development of networks of urban green spaces. This article presents a study that used a GIS-based least cost path (LCP) analysis to identify the best alternative for developing an urban green space network in the coastal city of Jakarta, Indonesia, which was based on the evaluation of topography and land use characteristics. Pair-wise analysis was used to reduce the sensitivity in the LCP model. The results showed that the coastal wetlands in the northern part of Jakarta and the agricultural fields in the suburban areas of Jakarta play an important role in connecting the green space network. On the other hand, some green spaces in the central part of Jakarta could not be connected by the LCP model. The method used in this study can serve as a tool to support the identification of networks of potential urban green spaces. It can also provide useful information for sustainable urban landscape planning and management in urban ecosystems. However, the inclusion of socio-economic criteria would further improve the model.

A Study on the Criteria for Demarcating Ecological Types of Urban Areas by the Affection of Ecosystems - Case Study in Gangdong-Gu, Seoul - (시가화지역 생태적 유형구분을 위한 관련지표 특성 연구 - 서울시 강동구를 사례로 -)

  • Hong, Suk-Hwan;Lee, Kyong-Jae
    • Journal of the Korean Institute of Landscape Architecture
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    • v.36 no.2
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    • pp.24-31
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    • 2008
  • Studies for demarcation of urban areas by ecological type have been developed, but the demarcation of urban areas by ecological perception is thus far dependent on artificial land use. Therefore, the purpose of this study is to find factors that account for the urban area ecosystems by surveying a variety of ecosystem factors. By land use type, the urban area of Gangdong District, Seoul was defined. Then ecological factors in each polygon were surveyed. Ecological factors are associated with energy use(building coverage ratio, floor area ratio and ground temperature), water circulation(biotope area factors and impermeable pave ratio) and biological diversity(bird appearance index and green area ratio). The correlation between each factor was analyzed. The results indicate that urban ground temperature is divided into three groups(high, middle and low) by the biotope area factor. The bird population is divided into two groups(abundant and scarce) by the green area ratio. Therefore, demarcating the urban areas by ecological type is applicable to the biotope area factor and green area ratio.

Detection of Individual Trees in Human Settlement Using Airborne LiDAR Data and Deep Learning-Based Urban Green Space Map (항공 라이다와 딥러닝 기반 도시 수목 면적 지도를 이용한 개별 도시 수목 탐지)

  • Yeonsu Lee ;Bokyung Son ;Jungho Im
    • Korean Journal of Remote Sensing
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    • v.39 no.5_4
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    • pp.1145-1153
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    • 2023
  • Urban trees play an important role in absorbing carbon dioxide from the atmosphere, improving air quality, mitigating the urban heat island effect, and providing ecosystem services. To effectively manage and conserve urban trees, accurate spatial information on their location, condition, species, and population is needed. In this study, we propose an algorithm that uses a high-resolution urban tree cover map constructed from deep learning approach to separate trees from the urban land surface and accurately detect tree locations through local maximum filtering. Instead of using a uniform filter size, we improved the tree detection performance by selecting the appropriate filter size according to the tree height in consideration of various urban growth environments. The research output, the location and height of individual trees in human settlement over Suwon, will serve as a basis for sustainable management of urban ecosystems and carbon reduction measures.

Long-term impacts of Argentine ant invasion of urban parks in Hiroshima, Japan

  • Park, Sang-Hyun;Hosoishi, Shingo;Ogata, Kazuo
    • Journal of Ecology and Environment
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    • v.37 no.3
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    • pp.123-129
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    • 2014
  • Ant communities are well suited for monitoring changes in ecosystems. Although numerous studies have examined the responses of ant communities to environmental disturbance, relatively few long-term studies on ant communities have been undertaken in urban environments. We examined species richness in nine urban parks in Hiroshima, Japan, and compared the survey results with data collected at the same sites by using the same methods in 1999. In both surveys, total of 25 species was recorded: 23 species in 1999 and 20 species in 2012. Non-metric multidimensional scaling analysis revealed that the ant communities consisted of two distinct groups, which could in turn be characterized by three patterns of ant community changes in between the two groups. The first of these community change patterns was characterized by a shift within group 1, but the number of species remained constant (approx. 10 species). The second pattern was characterized by a shift within group 2, but the number of species remained low (approx. 4 species). The third pattern was characterized by a shift from group 1 to group 2 as the abundance of Linepithema humile (Mayr) increased over time. Unlike the first and second patterns, the number of ant species in communities of the third type decreased significantly. These findings suggest that L. humile has a marked effect on the species diversity of indigenous ant communities in urban environments.