以MODIS與Landsat 8影像評估都市冷島強度

Applying MODIS and Landsat 8 Images for Evaluating Urban Cool Island Effect

周孜恆(Tzu-Heng Chou) ； 林毓琪(Yu-Qi Lin) ； 王聖鐸(Sendo Wang)

《航測及遙測學刊》 24卷4期 (2019/12) Pp. 223-233

https://doi.org/10.6574/JPRS.201912_24(4).0002

摘要

本研究以臺北市為研究區，利用多時期MODIS和Landsat 8影像所提供之大尺度地表溫度，觀察臺北市中心綠地分布、大小和都市冷島效應的關係，進而評估都市冷島強度，並分析其差異性。此外也利用氣象局地面氣象站所提供的氣溫驗證，評估兩種影像是否能應用於評估都市冷島強度。研究結果顯示Landsat 8和MODIS影像所反演之地表溫度與地面氣象站氣溫皆為高度正相關。以Landsat 8影像計算之結果顯示，臺北市公園都市冷島強度在春天和夏天較高，其中大安森林公園在春天的冷島強度達到1.92°C。最後分析都市公園面積和該公園都市冷島強度之相關性，R^2值為0.4852為中度相關。

關鍵字

MODIS ； Landsat 8 ； 地表溫度 ； 都市冷島

並列摘要

Both MODIS and Landsat 8 provide the land surface temperature (LST) images, but their images are slightly different both in the spatial resolution and in the calculation of LST. The MODIS retrieves LST from thermal infrared response at the spatial resolution of 1 kilometer, whereas the Landsat 8 images retrieve LST from band 10 and 11 thermal infrared response with the spatial resolution of 30 meters. These differences are the focus of this paper and are evaluated in the process of finding urban cool islands (UCI). Taipei City is selected as our research area. The heat generated from high-rise buildings and artificial impervious surfaces in Taipei results in the urban heat islands. Yet, there are also several urban parks with high-density vegetation coverage where can cool down the surface temperature of the city. Thus, we expect to acquire large-scale LST by multi-temporal MODIS and Landsat 8 images, considering the relationship between the green area in downtown and the spatial resolution of images, and assessing how large the green area may result in the UCI. Finally, we also use the temperature actually measured by the ground weather station for validation, analyzing whether both of two images can be used to evaluate the UCI effect.

並列關鍵字

MODIS ； Landsat 8 ； Land Surface Temperature (LST) ； Urban Cool Island (UCI)