• Title/Summary/Keyword: Urban Features

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Land Use Feature Extraction and Sprawl Development Prediction from Quickbird Satellite Imagery Using Dempster-Shafer and Land Transformation Model

  • Saharkhiz, Maryam Adel;Pradhan, Biswajeet;Rizeei, Hossein Mojaddadi;Jung, Hyung-Sup
    • Korean Journal of Remote Sensing
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    • v.36 no.1
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    • pp.15-27
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    • 2020
  • Accurate knowledge of land use/land cover (LULC) features and their relative changes over upon the time are essential for sustainable urban management. Urban sprawl growth has been always also a worldwide concern that needs to carefully monitor particularly in a developing country where unplanned building constriction has been expanding at a high rate. Recently, remotely sensed imageries with a very high spatial/spectral resolution and state of the art machine learning approaches sent the urban classification and growth monitoring to a higher level. In this research, we classified the Quickbird satellite imagery by object-based image analysis of Dempster-Shafer (OBIA-DS) for the years of 2002 and 2015 at Karbala-Iraq. The real LULC changes including, residential sprawl expansion, amongst these years, were identified via change detection procedure. In accordance with extracted features of LULC and detected trend of urban pattern, the future LULC dynamic was simulated by using land transformation model (LTM) in geospatial information system (GIS) platform. Both classification and prediction stages were successfully validated using ground control points (GCPs) through accuracy assessment metric of Kappa coefficient that indicated 0.87 and 0.91 for 2002 and 2015 classification as well as 0.79 for prediction part. Detail results revealed a substantial growth in building over fifteen years that mostly replaced by agriculture and orchard field. The prediction scenario of LULC sprawl development for 2030 revealed a substantial decline in green and agriculture land as well as an extensive increment in build-up area especially at the countryside of the city without following the residential pattern standard. The proposed method helps urban decision-makers to identify the detail temporal-spatial growth pattern of highly populated cities like Karbala. Additionally, the results of this study can be considered as a probable future map in order to design enough future social services and amenities for the local inhabitants.

Development of Stream Assessment Technique for Restoration and Management of Urban Stream (도시하천의 복원과 관리를 위한 하천평가기법 개발)

  • Song, Ju Il;Lee, Joon Ho;Yoon, Sei Eui
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3B
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    • pp.283-296
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    • 2008
  • The Urban Stream Assessment Technique (USAT) was suggested to give information about present urban stream condition. Domestic and foreign stream evaluation methods were analyzed and some streams were previously investigated to decide evaluation factors that could evaluate stream condition and have concern with characteristics and flood control of urban stream. The USAT consisted of three steps. High step has three characteristics concerned with functions of stream such as flood risk, stream, and ecology. In middle step, three characteristics were subdivided by ten features to describe changes and degradations of urban stream. Low step consisted of fifty three factors that explain the present condition of ten features. A survey of river experts was conducted to reflect weight among characteristics and features. The weights were calculated by analytic hierarchy process(AHP). The USAT was carried out to check over application of that in Suwon, Anyang, and Joongrang stream. The results of stream evaluation were expressed by factor index, feature index, characteristic index, total index, and evaluation grade. The results of the USAT were useful to realize changed and degraded areas. It is expected that the USAT can be used as base investigation for restoring and managing urban streams.

Consideration of NDVI and Surface Temperature Calculation from Satellite Imagery in Urban Areas: A Case Study for Gumi, Korea

  • Bhang, Kon Joon;Lee, Jin-Duk
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.1
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    • pp.23-30
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    • 2017
  • NDVI (Normalized Difference Vegetation Index) plays an important role in surface land cover classification and LST (Land Surface Temperature Extraction). Its characteristics do not full carry the information of the surface cover typically in urban areas even though it is widely used in analyses in urban areas as well as in vegetation. However, abnormal NDVI values are frequently found in urban areas. We, therefore, examined NDVI values on whether NDVI is appropriate for LST and whether there are considerations in NDVI analysis typically in urban areas because NDVI is strongly related to the surface emissivity calculation. For the study, we observed the influence of the surface settings (i.e., geometric shape and color) on NDVI values in urban area and transition features between three land cover types, vegetation, urban materials, and water. Interestingly, there were many abnormal NDVI values systematically derived by the surface settings and they might influence on NDVI and eventually LST. Also, there were distinguishable transitions based on the mixture of three surface materials. A transition scenario was described that there are three transition types of mixture (urban material-vegetation, urban material-water, and vegetation-water) based on the relationship of NDVI and LST even though they are widely distributed.

URBAN COMPLEXITY ESTIMATION INDICES BASED ON 3D DISCRETE WAVELET TRANSFORM OF REMOTELY SENSED IMAGERY;THE PRELIMINARY INTERPRETATION WITH LAND COVER MAP

  • Yoo, Hee-Young;Lee, Ki-Won;Kwon, Byung-Doo
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.405-409
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    • 2007
  • Each class in remotely sensed imagery has different spectral and spatial characteristics. Natural features have relatively smaller spatial changes than spectral changes. Meanwhile, urban area in which buildings, roads, and cars are included is inclined to face more changes of spatial variation than spectral one. This study aims to propose the new urban complexity index (UCI) based on the 3D DWT computation of remotely sensed imageries considering these characteristics. And then we analyze relation between index and land cover map. The 3DWUCI values are related to class and the indices of urban area are greater than natural area. The proposed UCI could be used to express effectively the standard of urban complexity over a wide area.

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Research on Vertical Space System of Mixed-Use Complex

  • Wang, Zhendong;Wang, Yinpu
    • International Journal of High-Rise Buildings
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    • v.4 no.2
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    • pp.153-160
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    • 2015
  • As the predominant mode of vertical urban development in China, mixed-use complexes provide the optimal case for the research of sustainable and vertical urbanism. This paper reviews three typical mixed-use complexes with various vertical space systems in Shanghai via the combination of field observation, questionnaires and software analysis. It then proceeds to determine which vertical space system is most effective for encouraging sustainable vertical urban development from the perspective of spatial efficiency. Finally, it concludes with an evaluation of the relative capabilities of the design features of a mixed-use complex: to create external dimensional-connections, to create multiple internal connections, and to organize overall composite functions.

To Protect and Utilize Suburban Green Space and To Expend Green Ecological Space at Urban Periphery

  • Dinghua Liu;Yaojiong Mei
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • no.2
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    • pp.164-170
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    • 2004
  • Suburban green space is an important component part of urban ecological system, the third largest space between urban center and peripheral countryside. Because of the specific regional location of the suburban green space, it differs from the green space in the center of the city in the respects of construction and planning. Anyhow, it has the features of less investment, quicker efficiency, free and easy management and good ecological effects. The writer of this paper holds that urban ecological construction should be planned rationally and laid out in an overall way under the prerequisite of making full use of and protecting local species so as to further extend the green ecological space at urban periphery, to create dense green surroundings, and to explore a way for ecological construction to develop in a scientific, effective and healthy way.

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Building Wind Corridor Network Using Roughness Length (거칠기길이를 이용한 바람통로 네트워크 구축)

  • An, Seung Man;Lee, Kyoo-Seock;Yi, Chaeyeon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.3
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    • pp.101-113
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    • 2015
  • The purpose of this study is increasing ventilation network usability for urban green space planning by enhancing its practicality and detail. A ventilation network feature extraction technique using roughness length($z_0$) was proposed. Continuously surfaced DZoMs generated from $z_0$(cadastral unit) using three interpolations(IDW, Spline, and Kriging) were compared to choose the most suitable interpolation method. Ventilation network features were extracted using the most suitable interpolation technique and studied with land cover and land surface temperature by spatial overlay comparison. Results show Kriging is most suitable for DZoM and feature extraction in comparison with IDW and Spline. Kriging based features are well fit to the land surface temperature(Landsat-7 ETM+) on summer and winter nights. Noteworthy is that the produced ventilation network appears to mitigate urban heat loads at night. The practical use of proposed ventilation network features are highly expected for urban green space planning, though strict validation and enhancement should follow. (1) $z_0$ enhancement, (2) additional ventilation network interpretation and editing, (3) linking disconnected ventilation network features, and (4) associated dataset enhancement with data integrity should technically preceded to enhance the applicability of a ventilation network for green space planning. The study domain will be expanded to the Seoul metropolitan area to apply the proposed ventilation network to green space planning practice.

Analysis on the Effects of Building Coverage Ratio and Floor Space Index on Urban Climate (도시의 건폐율 및 용적률이 도시기후에 미치는 영향 분석)

  • Yeo, In-Ae;Yee, Jurng-Jae;Yoon, Seong-Hwan
    • Journal of the Korean Solar Energy Society
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    • v.29 no.3
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    • pp.19-27
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    • 2009
  • In this study, Urban Climate Simulation was performed by 3-Dimensional Urban Canopy Model. The characteristics of urban climate were analyzed combining artificial land coverage, building size, heat production from the air conditioning and topographic conditions as physical variables which affects urban climate characteristics. The results are as follows. (1) The aspects of the urban climatal change is derived to be related to the combination of the building coverage ratio, building height and shading area. According to the building height, the highest temperature was increased by $2.1^{\circ}C$ from 2-story to 5-story building and the absolute humidity by 2.1g/kg maximum and the wind velocity by 1.0m/s was decreased from 2-story to 20-story building. (2) Whole heat generation was influenced by the convective sensible heat at the lower building height and by the artificial heat generation at the higher one over 20-story building influence to some extent of the building coverage ratio. The effect of the altitude is not more considerable than the other variables as below $1^{\circ}C$ of the air temperature. In the last, deriving the combination of building coverage and building height is needed to obtain effectiveness of the urban built environment planning at the point of the urban climate. These simulation results need to be constructed as DB which shows urban quantitative thermal characters by the urban physical structure. These can be quantitative base for suggesting combinations of the building and urban planning features at the point of the desirable urban thermal environment as well as analyzing urban climate phenomenon.

Study on Urban Policies toward the Effective Disaster Prevention (실효성 있는 재해예방형 도시계획을 위한 개선방향 고찰)

  • Kim, Seulyea;Kim, Mieun;Kim, Changhyun;Lee, Sangeun
    • Journal of the Korean Society of Safety
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    • v.32 no.2
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    • pp.124-131
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    • 2017
  • This study aims to contribute to urban policy for more effective disaster prevention, as abnormal natural disasters are becoming more frequent. Up to now, the urban plan for disaster prevention in Korea merely includes basic principles and necessities of measures as an early stage. Furthermore, there are difficulties to make specific programs because the legal system, technical instruments, and financial supports are not sufficient. Therefore, this study figures out problems in the current plan related to urban prevention after analyzing the legal system and practices. Resulting from case studies in developed countries, the study draws significant implications, as follows: enhancing legally binding force; improving the procedures for the programs; establising technical infrastructure. It first suggests a way for the urban policy for disaster prevention by considering our local features comprehensively. It then defines the roles of central, local governemnts and research institutions, and the procedure for urban disaster prevention planning building on the individual roles. This study concludes that an emphasis should be placed on institutional tools necessary to publish technical guideline and establish the system so that urban planners more easily access to disaster risk information.

A Study on Community Revitalization Policy through Analysis of Urban Regeneration Cases -Focussing on the Cases of the Urban Regeneration in the UK, Germany and Korea- (도시재생 사례분석을 통한 커뮤니티 활성화 정책에 관한 연구 -영국·독일·한국의 도시재생 사례를 중심으로-)

  • Jang, Yong Il;Kim, Chang-Sung
    • KIEAE Journal
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    • v.16 no.5
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    • pp.93-101
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    • 2016
  • Purpose : This research aims to present policy plans for community vitality in the field of the urban regeneration project by analyzing aspects for vitality via domestic and abroad city policies and cases. Methods: The research method works as follows: The first step is 1) to introduce the concept of evaluation matrix to analyze cases of urban generation, 2) to apply to the proposed evaluation matrix, and then 3) to analyze communities' decline diagnosis, counterstrategies, and promotion process. And the second step is to draw features and evaluation of cases and to present the policy plan for communities' vitality with the urban regeneration project in South Korea via a comprehensive analysis. Result : This research confirmed the fact that when different sectors is expanded toward a mutual cooperation, communities are vitalized, having a mutual effect on other related sectors by taking a part in the community positively. Especially in the base of each characteristic and estimation, when various activities and socio-economic programs with residents are promoted in the integrated system, communities are successful. Through this results we present four policy plans for community vitality of the urban regeneration project in South Korea.