• Title/Summary/Keyword: Urban Change

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Development and Evaluation of a Texture-Based Urban Change Detection Method Using Very High Resolution SAR Imagery (고해상도 SAR 영상을 활용한 텍스처 기반의 도심지 변화탐지 기법 개발 및 평가)

  • Kang, Ah-Reum;Byun, Young-Gi;Chae, Tae-Byeong
    • Korean Journal of Remote Sensing
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    • v.31 no.3
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    • pp.255-265
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    • 2015
  • Very high resolution (VHR) satellite imagery provide valuable information on urban change monitoring due to multi-temporal observation over large areas. Recently, there has been increased interest in the urban change detection technique using VHR Synthetic Aperture Radar (SAR) imaging system, because it can take images regardless of solar illumination and weather condition. In this paper, we proposed a texture-based urban change detection method using the VHR SAR texture features generated from Gray-Level Co-Occurrence Matrix (GLCM). In order to evaluate the efficiency of the proposed method, the result was compared, visually and quantitatively, with the result of Non-Coherent Change Detection (NCCD) which is widely used for the change detection of VHR SAR image. The experimental results showed the greater detection accuracy and the visually satisfactory result compared with the NCCD method. In conclusion, the proposed method has shown a great potential for the extraction of urban change information from VHR SAR imagery.

A Preliminary Analysis of the Impact of Urban Green Spaces on the Urban Heat Island Effect Using a Temperature Map

  • Myeong, Soo-Jeong
    • Korean Journal of Remote Sensing
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    • v.26 no.6
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    • pp.675-680
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    • 2010
  • Temperature is one of the main issues in climate change, and the urban heat island effect in highly developed urban areas is an important issue that we need to deal with. This study analyzed the extent of the cooling effects of urban green spaces. The study used a surface temperature map of Seoul. It found that the cooling effects of green space was observed within limited distances, although it varied a little depending on the parks investigated. The cooling effect distance ranged from 240m to 360m, averaging about 300m. It also found the size of an urban green space does not make much difference in cooling the surrounding areas. Although further investigation with diverse urban areas should be conducted on this matter, the results did imply that many small green spaces in the neighborhood are more effective than a single big green space in mitigating the heat island effects of cities.

Grid Unit Based Analysis of Climate Change Driven Disaster Vulnerability in Urban Area (격자단위 분석기법을 적용한 도시 기후변화 재해취약성분석)

  • Hong, Jeajoo;Lim, HoJong;Ham, YoungHan;Lee, ByoungJae
    • Spatial Information Research
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    • v.23 no.6
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    • pp.67-75
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    • 2015
  • Today, because human settlements are concentrated into urban area, urban planning and management technique considering the complexity, diversity, and advanced situations of urban living space is being requested. Especially, to effectively respond to large and diverse climate change driven disaster, it is necessary to develop urban planning technique including land use, infrastructure planning based on disaster vulnerability analysis. However, because current urban climate change disaster vulnerability analysis system(UC-VAS) is using census output area as spatial analysis unit, it is difficult to utilize the analysis results for specific urban planning. Instead, this study applies the grid manner to two study areas. The analysis results show that it can generate more detailed results and it can be used for detailed zoning decision by comparing with areal photos. Furthermore, by describing the limitation of the grid manner and providing professional way to secure additional scientific character and objectivity of the future urban climate change disaster vulnerability analysis system, it is expected that this study contributes to the effectiveness of system management.

Development of technology to predict the impact of urban inundation due to climate change on urban transportation networks (기후변화에 따른 도시침수가 도시교통네트워크에 미치는 영향 예측 기술 개발)

  • Jeung, Se Jin;Hur, Dasom;Kim, Byung Sik
    • Journal of Korea Water Resources Association
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    • v.55 no.12
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    • pp.1091-1104
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    • 2022
  • Climate change is predicted to increase the frequency and intensity of rainfall worldwide, and the pattern is changing due to inundation damage in urban areas due to rapid urbanization and industrialization. Accordingly, the impact assessment of climate change is mentioned as a very important factor in urban planning, and the World Meteorological Organization (WMO) is emphasizing the need for an impact forecast that considers the social and economic impacts that may arise from meteorological phenomena. In particular, in terms of traffic, the degradation of transport systems due to urban flooding is the most detrimental factor to society and is estimated to be around £100k per hour per major road affected. However, in the case of Korea, even if accurate forecasts and special warnings on the occurrence of meteorological disasters are currently provided, the effects are not properly conveyed. Therefore, in this study, high-resolution analysis and hydrological factors of each area are reflected in order to suggest the depth of flooding of urban floods and to cope with the damage that may affect vehicles, and the degree of flooding caused by rainfall and its effect on vehicle operation are investigated. decided it was necessary. Therefore, the calculation formula of rainfall-immersion depth-vehicle speed is presented using various machine learning techniques rather than simple linear regression. In addition, by applying the climate change scenario to the rainfall-inundation depth-vehicle speed calculation formula, it predicts the flooding of urban rivers during heavy rain, and evaluates possible traffic network disturbances due to road inundation considering the impact of future climate change. We want to develop technology for use in traffic flow planning.

The Changes of Adjacent Residential Area after the Restoration of Covered Urban Streams (도시복개하천의 복원사업 이후 인접 주거지의 물리적 특성 변화)

  • Kim, Jun-Yeong;Yang, Woo-Hyun
    • Journal of the Korean housing association
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    • v.25 no.6
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    • pp.133-146
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    • 2014
  • This study aims to analyze the changes of adjacent residential area after the restoration of covered urban streams in seoul. The changes of adjacent residential area after restoration were analyzed by changes of land using, urban structure, individual lot of land and architecture to investigate relationship of the urban stream and residential change. The result as follows: the first one is the change of land use and urban structure in adjacent residential area. This change of infrastructure through stream restoration has transformed land use and urban structure in adjacent residential area. Secondly, there is the changes of the individual lot of land. It seemed that new development by combined lots would be concentrated in stream-side blocks. But, the changes of lots such as combining or dividing lots tend to be concentrated in stream-side, main road and main streets. In stream-side, commercial function of land use has changed to residential one which has restored streams landscape by transformation of lots use without changes of ownership-lots. Finally, there is the change of architecture. It turned out new building in adjacent residential area is similar to general development. However, new building in streamside is related to direction of stream. In addition, remodeling and expansion tend to change in commercial buildings on stream-side bridges of corner lots intensively. As a result, it is related to expectation of architectural activation and improvement of sidewalk environment by stream restoration.

Low Impact Urban Development For Climate Change and Natural Disaster Prevention

  • Lee, Jung-Min;Jin, Kyu-Nam;Sim, Young-Jong;Kim, Hyo-Jin
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.54-55
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    • 2015
  • Increase of impervious areas due to expansion of housing area, commercial and business building of urban is resulting in property change of stormwater runoff. Also, rapid urbanization and heavy rain due to climate change lead to urban flood and debris flow damage. In 2010 and 2011, Seoul had experienced shocking flooding damages by heavy rain. All these have led to increased interest in applying LID and decentralized rainwater management as a means of urban hydrologic cycle restoration and Natural Disaster Prevention such as flooding and so on. Urban development is a cause of expansion of impervious area. It reduces infiltration of rain water and may increase runoff volume from storms. Low Impact Development (LID) methods is to mimic the predevelopment site hydrology by using site design techniques that store, infiltrate, evaporate, detain runoff, and reduction flooding. Use of these techniques helps to reduce off-site runoff and ensure adequate groundwater recharge. The contents of this paper include a hydrologic analysis on a site and an evaluation of flooding reduction effect of LID practice facilities planned on the site. The region of this Case study is LID Rainwater Management Demonstration District in A-new town and P-new town, Korea. LID Practice facilities were designed on the area of rainwater management demonstration district in new town. We performed analysis of reduction effect about flood discharge. SWMM5 has been developed as a model to analyze the hydrologic impacts of LID facilities. For this study, we used weather data for around 38 years from January 1973 to August 2014 collected from the new town City Observatory near the district. Using the weather data, we performed continuous simulation of urban runoff in order to analyze impacts on the Stream from the development of the district and the installation of LID facilities. This is a new approach to stormwater management system which is different from existing end-of-pipe type management system. We suggest that LID should be discussed as a efficient method of urban disasters and climate change control in future land use, sewer and stormwater management planning.

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A study on the Characteristics of Urban Dryness in Daegu (대구의 도시건조화 특성에 관한 연구)

  • Park, Myung-Hee;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.16 no.2
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    • pp.171-178
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    • 2007
  • It is well known that urban relative humidity has continuous decreasing trend owing to the influence of urbanization. The change of relative humidity is directly influenced by two factors, namely, temperature effect and water vapor effect in various urban effects. In this study, the temperature and tile water vapor effects on the relative humidity change were analyzed by using monthly mean relative humidities for a long period($1961{\sim}2005$) in Daegu and Chupungnung. The major results obtained in this study can be summarized as follows. Firstly, the urban dryness was caused mainly by water vapor effect in summer. But, for the other seasons, the urban dryness is mainly due to the temperature effect. Secondly, the relative humidity in Daegu is on the decrease until now. This phenomenon is similar to another Korean huge cities such as Seoul, Daejeon and Incheon. But, it is different compared with Japanese huge cities such as Tokyo, Osaka and Nagoya, indicating a standstill in relative humidity change after 1980s.

Application of Change Detection Techniques using KOMPSAT-1 EOC Images

  • Lee, Kwang-Jae;Kim, Youn-Soo
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.222-227
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    • 2002
  • This research will examine into the capabilities of KOMPSAI-1 EOC image application in the field of urban environment and at the same time, with that as its foundation, come to understand the urban changes of the study areas. This research is constructed in three stages: Firstly, for application of change detection techniques, which utilizes multi-temporal remotely sensed data, the data normalization process is carried out. Secondly, change detection method is applied fur the systematic monitoring of land use changes, which utilizes multi-temporal EOC images. Lastly, by using the results of the application of land use changes, the existing land use map is updated. Consequently, the land-use change patterns are monitored, which utilize multi-temporal panchromatic EOC image data; and application potentials of ancillary data fur updating existing data can be presented. In this research, with the use of the land use change, monitoring of urban growth has been carried out, and the potential for the application of KOMPSAT-1 EOC images and the scope of application was examined. Henceforth, the future expansion of the scope of application of KOMPSAT-1 EOC image is anticipated.

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The Difference between Financial Stability and Satisfaction according to Change-orientation of Urban Housewives' Family Financial Management Behavior (도시주부 가계재무관리행동의 변화지향성에 따른 가계재무건전성 및 재정만족도 차이)

  • Jeong, Mi-Sun;Kye, Sun-Ja;Kang, Hye-Kyoung
    • Journal of Families and Better Life
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    • v.26 no.5
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    • pp.391-403
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    • 2008
  • The purpose of the study was to find the level of family financial management behavior of urban housewives and to discern the difference between financial stability and financial satisfaction according to change-orientation of financial management behavior among urban housewives, and thus provide the fundamental data to improve stability and financial satisfaction. The following findings emerged during the study: First, groups with higher change-oriented family financial management behaviors among housewives subjectively felt more financial satisfaction than other groups. Second, groups with above average levels of change-oriented management behavior appeared to have more stable families than groups with below average objective financial stability, emergency funds, risk provisions, debt burdens and liquid index. Third, groups with high levels of change-oriented family financial management behavior had higher financial satisfaction.

Detection of Heat Change in Urban Center Using Landsat Imagery (Landsat 영상을 이용한 도심의 열변화 탐지)

  • Kang, Joon-Mook;Ka, Myung-Seok;Lee, Sung-Soon;Park, Joon-Kyu
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.2
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    • pp.197-206
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    • 2010
  • Recently, developed countries have continuously been trying to recognize many issues about heat island in urban area and to make up countermeasures for them. This research is designed to extract change of land cover in the area under condition of land development with satellite images and to analyze its effect on the heat change in there. Heat change upon change of land cover in daejeon was analyzed with the four Landsat satellite images taken in April 1985, August 1994, May 2001, and May 2009. In order to measure the temperature on the surface in the city, the land surface temperature was produced with Landsat TM Band 6. Heat change is to detected with it. As a result, The urban area has been increased up to 23.59 percent. On the other hand, the forest area has been decreased up to 27.91%. Due to the urbanization, the temperature on the surface in urban center was higher than surrounding area. In that case, the temperature of urban center area was higher 2.4 to $5.7^{\circ}C$ compared with the forest area.