Urban heat island effects derived from dense Landsat thermal observations in Nanjing, China
نویسندگان
چکیده
An urban heat island (UHI) is an urban area where temperatures are higher than they are in the surrounding suburban areas. UHIs are of great scientific concern in the context of global environmental change. As a result of rapid economic development over the past three decades, the urban area in China has increased significantly. In the present study, to objectively determine the spatiotemporal patterns of UHI effects in Nanjing, surface brightness temperatures of the urban areas of Nanjing, which originated from remote sensing imagery of Landsat TM/ETM+ from 1988 to 2011, were inversed, and then the UHIs were extracted and graded by choosing a stable forest area as the suburban reference. When the results were combined with the surface meteorological data, a good relationship was found between the brightness temperatures and the ground-truth temperatures. The results of contrast analysis indicated that, over time, most of the heat islands of Nanjing remained over the central portions. The area and the intensity of the heat islands have both increased remarkably over the past 20
منابع مشابه
Spatial and Temporal Analysis of the Mitigating Effects of Industrial Relocation on the Surface Urban Heat Island over China
Urbanization is typically accompanied by the relocation and reconstruction of industrial areas due to limited space and environmental requirements, particularly in the case of a capital city. Shougang Group, one of the largest steel mill operators in China, was relocated from Beijing to Hebei Province. To study the thermal environmental changes at the Shougang industrial site before and after r...
متن کاملAn Emissivity Modulation Method for Spatial Enhancement of Ther mal Satellite Images in Urban Heat Island Analysis
This study examines and validates a technique for spatial enhancement of thermal satellite images for urban heat island analysis, using a nighttime ASTER satellite image. The technique, termed Emissivity Modulation, enhances the spatial resolution while simultaneously correcting the image derived temperatures for emissivity differences of earth surface materials. A classified image derived from...
متن کاملThe Investigation of Variability of Heat Island Hazard According to Land Use and Land Cover Changesin Esfahan
Abstract Urban heat island (UHI) is one of the environmental phenomenon which has made difficult environmental conditions for citizen. This study aims to evaluate the spatial and locational variability of Esfahan urban heat island according to the role of land use. Thus an area about 190.2 square kilometers (km2) in Esfahan, as the microclimate, was studied. In order to analyze the relations...
متن کاملRemote sensing for urban heat and cool islands evaluation in semi-arid areas
Cities are experiencing rapid population growth and consequently extensive urbanization. Land-use/land-cover change is one of the important elements worldwide, which significantly affect the environment. This study aims to describe the emergence of urban heat and cool islands as a result of changes in land-use/land-cover. Land surface temperature over a 32-year period in Isfahan city, Iran was ...
متن کاملA satellite remote sensing based assessment of urban heat island in Lanzhou city , northwest China
As a promising application, quantitative remote sensing of urban heat island (UHI) could facilitate our understanding of urban/suburban environment and its relationship with urbanization. This paper investigates the urban heat island effect of Lanzhou, China, a densely built up city in a valley, based on Landsat ETM+ image acquired on April 22, 2000, whose spatial resolution is sufficient for m...
متن کامل