Papers - Yan, Wanglin

Estimation of Urban Heat Island Intensity with Landsat/TM Thermal Images

YAN Wanglin and Takehiko Mikami

Journal of Geography (Tokyo Geographical Society)  113 ( 4 ) 482-494 - 494 2004.08

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0022-135X

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Urban Heat Island, a meteorological phenomenon that the air temperature in urban area raises more than suburbs, grows with the progress of urbanization. The difference of air temperatures between city center and suburbs is called Urban Heat Island Intensity (UHII). UHII is usually calculated as the fluctuation of the highest and lowest value of the ground-observed air temperatures. However, the magnitude of UHII may vary with the locations of observations. Satellite remote sensing has been expected as an effective way for obtaining thermal information of the earth surface with high resolution. However, the possibility and the way to evaluate UHII with brightness temperature (BTUHII) from satellite images have not been verified yet. This paper, taking Tokyo as study area, aims to clarify the method for calculating BTUHII with Landsat/TM thermal images and verifying its usability with in situ ATUHII. Based on the principle of ATUHII, we considered that BTUHII must be estimated with the same spatial resolution as the spatial scale that air temperatures are formed. This is called resolution condition. Moreover, the highest and the lowest temperatures for BTUHII must come from the similar land uses with those for ATUHII. This is called land use condition. Our previous research has shown that the brightness temperatures reach a maximal correlation with air temperatures in the distance about 600m in Tokyo. Invoking this result, we improved the spatial resolution of brightness temperature by applying a low path filter to the Landsat/TM night thermal image dated on March 1, 1999. For matching land use condition, we regrouped the 10m high-resolution land use data into 8 land use categories according to the brightness temperature and NDVI. In addition, we divided the study area from city center to suburbs into 6 zones: CBD, SubCBD, within 10km, 10-20km, 20-30km, and beyond 30km for taking account the impact of land uses in different distance sphere. As the results, the following facts have been successfully confirmed. (1) In the urban context like Tokyo, resampling brightness temperature image into resolution 500m can effectively remove the influence of cooling or heating facilities and make the spatial structure of UHII much clearer. (2) BTUHII is a little smaller than ATUHII but still comparable with each other. (3) Although BTUHII can’t substitute for ATUHII completely, the trend of BTUHII decreasing from city center to suburb is coincident with ATUHII so that BTUHII would be an effective indicator for the comparison of thermal attributes between different urban districts or land use categories. We believe that these conclusions have great significance for using satellite sensed thermal images in the research of urban climatology and the practice of urban planning.

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自然資本の運用による環境保全と社会発展のためのフレームワークの構築-チンハイ・チベット高原を事例として-

Wanglin YAN

総合政策学ワーキングペーパシリーズ (慶應義塾大学大学院政策・メディ研究科)   ( 37 ) 1-14 2004.06

Research paper (scientific journal), Single Work

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中国政府は21世紀の初頭に西部大開発戦略を打ち出し、西部地区に新たな発展のチャンスをもたらした。しかし、地理的および社会的条件の制約が大きいため、西部開発は東部沿海地域と同じ方法ではうまくいかない。一方、自然資本の概念や京都議定書が提唱したクリーン開発メカニズム（CDM）は我々に新しい考え方と仕組みを提供してくれた。これをもとにして世界各地において自然資本の評価や市場メカニズムの構築が研究・実践されている。本稿は自然資本の概念と国連ミレニアムアセスメント（MA）が提唱したエコシステムアセスメントの方法をチンハイ・チベット高原に適用するフレームワークを提示したものである。それは(１)高原地域のエコシステムの調査、(２)高原のエコシステムサービスの評価、(３)エコシステムサービスを持続可能にする地域政策の設計、及び(４)自然資本の市場メカニズムの構築、という４つの部分から構成されている。そのフレームワークを実施することにより、中国の西部と東部の間、そして中国と世界との間において、生態環境の改善につとめる人とそのサービスを受ける人が市場によって一体化されることになり、環境保全と経済発展と人間福祉という多数の目標を協調して達成させることが可能となる。

地域エコシステムのマッピングとエコシステムサービスの評価－地域環境ガバナンスのためのGISツールの適用

Wanglin YAN, Aya MATSUZAKI and Mikako SHIGIHARA

総合政策学ワーキングペーパシリーズ (慶應義塾大学大学院政策・メディ研究科)   ( 6 ) 1-17 2003.12

Research paper (scientific journal), Single Work

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This study attempts to map the spatial structure of regional ecosystems and to value the ecosystem services for environmental governance with a community-based GIS tool called CITYgreen. We practiced a multi-scale approach to map a wide region with satellite images for regional ecomap, geographic datasets for district ecomap and field survey for community ecomap. These three ecomaps have different ecotope categories and could be used for urban and regional planning, environmental design and local environmental conservation activities. Regardless of the scales, the ecomaps provide three functions: inventorying elements of ecosystems, analyzing the spatial structures of ecosystems and valuing ecosystem services such as the fixation and sequestration of carbon dioxide and filtration of atmospheric pollutants etc. Yokohama City, Tsuzuki Ward, a residential quarter have been selected as study areas at the three scales respectively. The experimental ecomaps show that this is an effective method to grasp the complex of regional ecosystems spatially and the tool is applicable to calculate ecosystem services for public participated regional environment improvement.

衛星熱画像を用いた都市域の温度分布特性の分析

Toshihiro HARUKI, Wanglin YAN and Hiromi Kobori

地理情報システム学会講演論文集 (地理情報システム学会)  12   115-118 2003.10

Research paper (conference, symposium, etc.), Joint Work

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The thermal characteristics of Tokyo Metropolitan Area and Yokohama City were analyzed using the Landsat TM images to clarify the features of the urban heat island (UHI) phenomenon. Since high correlation between remotely observed brightness temperature and ground air temperature had verified under the definite conditions, spatial and field-data of brightness temperature obtained from the Landsat TM thermal images was used in this study. It was clarified that the temperature of the forests, parks, and the other green spaces in the southern Tokyo Metropolitan Area is lower than the average temperature in the region. As a result, these green spaces could contribute to ease UHI phenomenon in the Area. Ｉｎ the contrast, the temperature of these green spaces exceeds the average temperature in Northern Yokohama City, resulting in acceleration of UHI. More detailed analysis demonstrated the heat point sources as well as cool point sources within the both areas.

Measuring Urban Heat Island with Landsat TM thermal image

Wanglin YAN

International Conference on Computers on Urban Planning and Urban Management  2003.05

Research paper (conference, symposium, etc.), Single Work, Accepted

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Urban Heat Island (UHI) is a phenomenon that the air temperature in urban area is higher than suburbs. The difference of air temperature between downtown area and suburb is called UHI intensity (UHII). Satellite remote sensing is an effective way to capture thermal information spatially over a wide area with high resolution. However, the possibility and the method of measuring UHII with thermal images remain unclear so far. This paper examined the impacts of urban forms on the satellite-observed brightness temperature and the ground-observed air temperature, and discussed the quantitative method of measuring UHII with brightness temperature under certain conditions. Low-pass filter was applied to brightness temperature, and the UHII was evaluated by landscape categorizes and distance zones from the center business district to suburbs. It turns out that the brightness temperature data could give a comparable UHII with that of air temperature observed on the ground when spatial and landscape conditions are consistent with each other.

Mapping the spatial structure of urban ecosystems and calculating the value of trees in Yokohama City

Wanglin YAN and Aya MATSUZAKI

The 8th Inter-university Seminar on Asian Megacities  2003.03

Research paper (conference, symposium, etc.), Single Work

Autonomous intelligent system and its application in driving assistant of vehicle safety

Tao Yu, Li Zhong Yu, Zheng Wang, Wang Lin Yan

Gongku Jiaotong Keji/Journal of Highway and Transportation Research and Development 19 ( 6 ) 136 2002.12

Accepted,  ISSN  1002-0268

衛星画像による中国内蒙古自治区ホルチン沙地の砂漠化の解析

Wanglin YAN and takuro OKAMOTO

地理情報システム学会講演論文集 12   397-400 2002.10

Research paper (conference, symposium, etc.), Single Work

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This study aims to extract the land cover changes and the development of desertification in Kerqin Sandland, Inner Mongolia of China with temporal satellite images. The landscape of Kerqin sandland is characterized with bright dunes, moist lower land and green grassland and forest. This structure well matches with the brightness, wetness and greenness of the Tasseled Cap Transformation of TM data. With this spectral transformation, we classified the land covers and evaluated the development of desertification with Landsat TM images from 1994 to 2000. This algorithm avoided the impact of different soil moisture between images and found that the desertified land in our study area in 2000 has doubled since 1994 while the restored forest and grassland only increased 50 percent.

Relationship between Surface Temperature from Landsat TM Thermal Images and Air Temperature Observed on the Ground

Wanglin YAN and Takehiko MIKAMI

Journal of Geography (Chigaku Zasshi) (Tokyo Geographical Society)  111 ( 5 ) 695-710 - 710 2002.10

Research paper (scientific journal), Joint Work,  ISSN  0022-135X

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This study, focusing on Tokyo Metropolitan Area, examined the statistical and spatial correlation between remotely observed brightness temperature and ground air temperature observation. Five scenes of thermal images of Landsat TM, including two daytime ones and three nighttime ones, and 72 stationary meteorological observations have been used as data sources.
The ground air temperature extracted from the meteorological records is compared with the satellite-estimated surface temperature for each data set and each radius from 100m to 1000m around meteorological stations separately. As the results, the following factors are concluded.
The correlation coefficient between ground-observed air temperature and satellite derived surface temperature could reach 0.9 under good observation condition. However, the magnitude of the coefficients is affected by weather conditions, time and date of data acquisition as well as spatial scale of data aggregation.
Wind speed not only affects the intensity of UHI but also the correlation coefficients of surface temperature and air temperature. The weaker the wind, the stronger is the UHI, and then the lager the coefficient between the two measurements.
The correlation coefficients between the two are weak in daytime images but strong in nocturnal images. This suggests that nocturnal thermal images prefer to capture the same structure of surface heat island with air heat island at night. Emissivity correction of surface temperature can enhance the correlation, but the intensity of improvement is uncertain. The gap of correlations between nocturnal images and daytime images could not be closed up enough with emissivity correction.
The surface temperature from the radiative power mainly influenced by urban canopy layer composed by micro land features. However, the ground air temperature is also affected by local or mesoscale urban boundary layer. This essential difference causes the correlation of surface temperature and air temperature spatial-dependently. The maximum of the correlation is within 600m around a meteorological station. Therefore, the range of 400-600m may be the reasonable distance for planners to discuss mitigation policy. This could also be a reference to decide the spatial resolution in simulation model.
The simple linear regressive equation in this paper could not be applied to other data and other city. However, this study successfully verified the possibility of transferring satellite derived surface temperature into air temperature. This is meaningful for researches and planners to explore the structure of heat islands or to discuss mitigation policies in microscale.

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ランドサットと地上同時観測によるTM熱画像の気温特性の分析

厳 網林

（社）日本リモートセンシング学会第28回学術講演会講演集    147-150 2000.05

Single Work

ITS空間情報技術への新たな挑戦

厳 網林

電気学会研究会資料産業システム情報化研究会  ( IIS-00-28〜39 ) 21-26 2000

Single Work

Chapter 12 Multimedia technologies for regional developments

厳 網林, Kiyoshi Kobayashi, Yasutaka Matsuo, Kenji Tsutsumi

Local Knowledge and Innovation: Enhancing the sustance of non-metropolitan regions" (Kyoto University)     121-131 1999.12

Joint Work

GIS and multimedia technologies for urban planning

厳 網林

Proceedings of International Workshop on GIS Application in Urban Planning and Management organized by UNCRD and the Ministry of Construction    216-232 1999.11

Single Work

An integrated utilization of GPS, RS and GIS for the analyses of urbanization in Shanghai

Wanglin Yan, Sachio Kubo

Proceedings of the 6th International Conference in Computers in Urban Planning and Urban Management  1999.07

Joint Work

高解像度リモートセンシングデータによる都市住宅形態の類型化－上海を事例として

厳 網林, 黄 少博，史中超

地理情報システム学会,  1998.10

Joint Work

高解像度リモートセンシングデータによる都市住宅形態の類型化－上海を事例として

厳 網林, 黄 少博，史中超

地理情報システム学会講演論文集 7   77-80 1998.10

Joint Work

Modeling Landscape Information for Visualization

厳 網林

International Conference on Modeling Geographical and Environmental Systems with Geographical Information Systems  1998.06

Single Work

地理情報システム(GIS)による都市空間の把握と分析

しばさきりょうすけ，げんもうりん

都市問題 (都市市政調査会)  88 ( 9 ) 69-82 1997.09

Research paper (scientific journal), Joint Work, Accepted

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都市に関するデータが増加する中で、GISはより高度な意思決定を目指す実務家を支援する有効なツールとなることが期待されている。本稿では地理情報システムの概念やGISで利用される基礎的なデータの整理状況などを概説した後、都市整備におけるGISの利用可能性について実例を含めて紹介した。

近代化に伴う上海市都市化の進展

げんもうりん，くぼさちお，いちまるのぶひろ

Journal of Geography (東京地学協会)  104 ( 4 ) 515-524 1995.08

Research paper (scientific journal), Joint Work, Accepted

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本研究は上海を対象に、GPSでGCPを実測し、RS画像を幾何補正する。各種の社会経済情報をGISにてデータベース化する。このようなGPS・RS・GISの統合的利用をもとに上海の都市化の現状を定量的に把握し、その原因を明らかにした。

A Knowledge Base and GIS Integrated System for Urban Planning

Wanglin YAN

GIS (GERMANY)  1995 ( 1 ) 10-14 1995.01

Research paper (scientific journal), Single Work, Accepted

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本研究は創造的な都市計画のためのGIS・CAD・知識ベース統合システムを構築しそのうちの重要なパーツである環境評価システムを開発した。様々な主観的・客観的な知識は認知工学手法を用いてモデル化し、知識ベースで管理・利用する。数学的統合モデルやファジィ的推論方法が評価システムにおいて有機的に融合された。