• Title/Summary/Keyword: Urban Sensing

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An Analysis of Urban Open Space with Geographic Information Systems - A Case Study of Ansan City, Korea - (지리정보체계를 이용한 안산시의 오픈스페이스 분석)

  • 서동조;박종화
    • Korean Journal of Remote Sensing
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    • v.6 no.2
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    • pp.89-113
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    • 1990
  • The purpose of this study is to develop means to apply GIS and remote sensing technology to the analysis of Korean urban open spaces. To achieve this objective, a framework of analysis of urban open spaces was developed, and then the framework was applied for the evaluation of the potential and suitability of open spaces of Ansan City, which is a new town developed to accomodate industries relocation from Seoul, Korea, mainly due to their pollution problems. The software used in this study are IDRISI, a grid-based GIS, and KMIPS, a remote sensing analysis system. Both packages are based on IBM PC/AT computers with Microsoft DOS. Landsat MSS and TM data were used for the land use classification, land use change detection, and analysis of transformed vegetation indices. The size of the geographic data base is 110 rows and 150 columns with the spatial resolution of 100m$\times$100m. The framework of analysis includes both quanititative and qualitative analysis of open spaces. The quantitative analysis includes size and distribution of open spaces, urban develpment of open spaces, and the degree of vegree of vegetation removal of the study area. The qualitative analysis includes evaluative criteria for primary productivity of land, park use potential, major visual resources, and urban environmental control. The findings of this study can be summarized as follows. First, the size of builtup areas increased 18.73km$^2$, while the size of forest land decreased 10.86km$^2$ during last ten years. Agricultural lands maintained its size, but shifted toward outside of the city into forest. Second, the potential of open spaces for park use is limited mainly due to their lack of accessibility and connectivity among open spaces, in spite of ample acreage and good site conditions. Third, major landscape elements and historic sites should be connected to the open space system of the city by new accesses and buffers.

IMPERVIOUS SURFACE ESTIMATION USING REMOTE SENSING IMAGES AND TREE REGRESSIOIN

  • Kim, Soo-Young;Kim, Jong-Hong;Heo, Joon;Heo, Jun-Haeng
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.239-242
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    • 2006
  • Impervious surface is an important index for the estimation of urbanization and environmental change. In addition, impervious surface has an influence on the parameters of rainfall-runoff model during rainy season. The increase of impervious surface causes peak discharge increasing and fast concentration time in urban area. Accordingly, impervious surface estimation is an important factor of urban rainfall-runoff model development and calibration. In this study, impervious surface estimation is performed by using remote sensing images such as landsat-7 ETM+ and high resolution satellite image and regression tree algorithm based on case study area ? Jungnang-cheon basin in Korea.

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Developing application system of forest information using digital photogrammetry and GIS

  • Jo, Myung-Hee;Heo, Young-Jin;Kim, Joon-Bum;Kim, In-Ho
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.911-913
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    • 2003
  • Recently in order to process forest official task more effectively and scientifically the previous of that which is focused on document and inventory, should be applied with the spatial information technology. Especially, the forest information remote sensing system has to be developed using digital photogrammetry and GIS. In this study the forest information remote sensing system is implemented to manage forest resource and forest official effectively especially by constructing database of forest environment information and cadastral information, overlaying various thematic maps, and performing spatial analysis using GIS and aerial photograph. For this, the attribute data and spatial data of aerial photograph, digital topography map, forest cadastral map, forest type map, forest use map should be reprocessed and stored in Oracle. Also, the user interface is developed by using Visual Basic 6.0 and MapObjects 2.1 of ESRI based on CBD(Component Based Development).

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Biotop Mapping Using High-Resolution Satellite Remote Sensing Data, GIS and GPS

  • Shin Dong-Hoon;Lee Kyoo-Seock
    • Korean Journal of Remote Sensing
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    • v.20 no.5
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    • pp.329-335
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    • 2004
  • Biotop map can be utilized for nature conservation and assessment of environmental impact for human activities in urban area. High resolution satellite images such as IKONOS and KOMPSAT1-EOC were interpreted to classify land use, hydrology, impermeable pavement ratio and vegetation for biotop mapping. Wildlife habitat map and detailed vegetation map obtained from former study results were used as ground truth data. Vegetation was investigated directly for the area where the detailed vegetation map is not available. All these maps were combined and the boundaries were delineated to produce the biotop map. Within the boundary, the characteristics of each polygon were identified, and named. This study investigates the possibility of biotop mapping using high resolution satellite remote sensing data together with field data with the goal of contributing to nature conservation in urban area.

AN ASSESSMENT OF LAND COVER CHANGES AND ASSOCIATED URBANIZATION IMPACTS ON AIR QUALITY IN NAWABSHAH, PAKISTAN: A REMOTE SENSING PERSPECTIVE

  • Shaikh, Asif Ahmed;Gotoh, Keinosuke
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.555-558
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    • 2006
  • In recent years, urban development has expanded rapidly in Nawabshah City of Pakistan. A major effect associated with this population trend is transformation of the landscape from natural cover types to increasingly impervious urban land. The core objective of this study are to provide time-series information to define and measure the urban land cover changes of Nawabshah, Pakistan between the years 1992 and 2002, and to examine related urbanization impacts on air quality of the study area. Two multi-temporal Landsat images acquired in 1992 and 2002 together with standard topographical maps to measure land cover changes were used in this study. The image processing and data manipulation were conducted using algorithms supplied with the ERDAS Imagine software. An unsupervised classification approach, which uses a minimum spectral distance to assign pixels to clusters, was used with the overall accuracy ranging from 84 percent to 92 percent. Land cover statistics demonstrate that during the study period (1992-2002) extensive transformation of barren and vegetated lands into urban land have taken place in Nawabshah City. Results revealed that land cover changes due to urbanization has not only contaminated the air quality of the study area but also raised the health concerns for the local residents.

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Analyzing the Evolution of Summer Thermal Anomalies in Busan Using Remote Sensing and Spatial Statistical Tool

  • Njungwi, Nkwain Wilfred;Lee, Daeun;Kim, Minji;Jin, Cheonggil;Choi, Chuluong
    • Korean Journal of Remote Sensing
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    • v.37 no.4
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    • pp.665-685
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    • 2021
  • This study focused on the a 20-year evaluation of the dynamism of critical thermal anomalies in Busan metropolitan area prompted by unusual infrastructural development and demographic growth rate. Archived Landsat thermal data derived-LST was the major input for UTFVI and hot spot analysis (Getis-Ord Gi*). Results revealed that the surface urban heat island-affected area has gradually expanded overtime from 23.32% to 32.36%; while the critical positive thermal anomalies (level-3 hotspots) have also spatially increased from 19.88% in 2000 to 23.56% in 2020, recording a net LST difference of > 5℃ between the maximum level-3 hotspot and minimum level-3 coldspot each year. It is been observed that thermal conditions of Busan have gradually deteriorated with time, which is potentially inherent in the rate of urban expansion. Thus, this work serves as an eye-opener to powers that be, to think and act constructively towards a sustainable thermal conform for city dwellers.

Satellite-based Drought Forecasting: Research Trends, Challenges, and Future Directions

  • Son, Bokyung;Im, Jungho;Park, Sumin;Lee, Jaese
    • Korean Journal of Remote Sensing
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    • v.37 no.4
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    • pp.815-831
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    • 2021
  • Drought forecasting is crucial to minimize the damage to food security and water resources caused by drought. Satellite-based drought research has been conducted since 1980s, which includes drought monitoring, assessment, and prediction. Unlike numerous studies on drought monitoring and assessment for the past few decades, satellite-based drought forecasting has gained popularity in recent years. For successful drought forecasting, it is necessary to carefully identify the relationships between drought factors and drought conditions by drought type and lead time. This paper aims to provide an overview of recent research trends and challenges for satellite-based drought forecasts focusing on lead times. Based on the recent literature survey during the past decade, the satellite-based drought forecasting studies were divided into three groups by lead time (i.e., short-term, sub-seasonal, and seasonal) and reviewed with the characteristics of the predictors (i.e., drought factors) and predictands (i.e., drought indices). Then, three major challenges-difficulty in model generalization, model resolution and feature selection, and saturation of forecasting skill improvement-were discussed, which led to provide several future research directions of satellite-based drought forecasting.

Analysis of Thermal Characteristics for Areas of Musim Stream in Cheongju City (청주시 무심천 주변의 열환경 특성 분석)

  • Park, Jin-Ki;Na, Sang-Il;Park, Jong-Hwa
    • Korean Journal of Agricultural Science
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    • v.37 no.1
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    • pp.81-86
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    • 2010
  • The urban thermal environment can be an important index to detect heat island phenomena and manage it to improve urban life quality. Cheongju is a typical plain-city that main part has been formed and developed in lowland. The Mushim stream crosses the city from south to north. We reviewed the use of thermal remote sensing in stream around areas and the thermal environments, focusing primarily on the Urban Heat Island(UHI) effect. The purpose of this study is to determine the relationship between the stream nearby urban area and the stream cooling effect of UHI. The objectives are to determine the usefulness of KOMPSAT-2 bands MS3 and MS4 for vegetation cover mapping, and the usefulness of LANDSAT TM band 6 in identifying thermal environmental characteristics and UHI. Land Surface Temperatures (LST) are retrieved by single-channel algorithm to study the UHI from the 6th band (thermal infrared band) of LANDSAT TM images and thermal radiance thermometer based on remote sensing method and the LST distribution maps are accomplished according to the retrieval results. There is also comparison of satellite-derived and in situ measured temperature. The results indicated that the LST of urban center is higher than that of suburban area, the temperature of mountain and water are the lowest area, so it is clearly proved that there are obvious UHI effects by stream. The surface temperature distribution of Mushim stream is detected $2^{\circ}C$ lower than urban area.

Analysis of Urban Surface Temperature Distribution Properties Using Spatial Information Technologies (공간정보기술을 활용한 도시지역 지표온도 분포 특성 해석)

  • Lee Kwang-Jae;Jo Myung-Hee
    • Korean Journal of Remote Sensing
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    • v.20 no.6
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    • pp.397-408
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    • 2004
  • In this study, surface temperature which was extracted from Landsat TM band 6 was compared and analyzed with the AWS(Automatic Weather System) observation data for studying urban heat environment properties with possibility of remote sensing data application. In order to verification of the distribution properties of urban surface temperature, correlation analysis between surface temperature and NDVI, the distribution properties of urban surface temperature by land use/cover patterns were carried out by GIS spatial analysis techniques. The results presented that the spatial distribution of urban surface temperature was very different depending on various land use/cover patterns of surrounding areas. Also there was the reverse linear relationship between surface temperature and NDVI. These results will be worked as one of the major factors for environmentally sustainable urban planning considering the characteristics of weather environments in the near future.

A Study on the Evaluation of the Different Thresholds for Detecting Urban Areas Using Remote-Sensing Index Images: A Case Study for Daegu, South Korea (원격탐사 지수 영상으로부터 도시 지역 탐지를 위한 임계점 평가에 관한 연구: 대구광역시를 사례로)

  • CHOUNG, Yun-Jae;LEE, Eung-Joon;JO, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.1
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    • pp.129-139
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    • 2019
  • Mapping urban areas using the earth observation satellites is useful for monitoring urban expansions and measuring urban developments. In this research, the different thresholds for detecting the urban areas separately from the remote-sensing index images (normalized-difference built-up index(NDBI) and urban index(UI) images) generated from the Landsat-8 image acquired in Daegu, South Korea were evaluated through the following steps: (1) the NDBI and UI images were separately generated from the given Landsat-8 image; (2) the different thresholds (-0.4, -0.2, and 0) for detecting the urban areas separately from the NDBI and UI images were evaluated; and (3) the accuracy of each detected urban area was assessed. The experiment results showed that the threshold -0.2 had the best performance for detecting the urban areas from the NDBI image, while the threshold -0.4 had the best performance for detecting the urban areas from the UI image. Some misclassification errors, however, occurred in the areas where the bare soil areas were classified into urban areas or where the high-rise apartments were classified into other areas. In the future research, a robust methodology for detecting urban areas, including the various types of urban features, with less misclassification errors will be proposed using the satellite images. In addition, research on analyzing the pattern of urban expansion will be carried out using the urban areas detected from the multi-temporal satellite images.