Analysis on the spatial distribution variation characteristic of urban heat environmental quality and its mechanism

Abstract

Urban heat environmental quality (UHEQ) is affected by the interacting of weather condition and underlying surface framework of urban area. In the last two decades, many researchers from domestic and overseas have studied many problems at the aspect of urban heat environment such as urban heat islands, urban air temperature and their relation with urban land cover, city population, air pollution etc. In the recent years, Hangzhou, acting as a center city of Zhejiang Province in China, its urbanization quantum and quantity have both changed greatly, in particular, representing as business affairs building, resident real property and all kinds of specialty market having arisen in built-up zone. Based on Landsat TM images data in 1991 and 1999, urban underlying surface temperature value and Normalized Difference Vegetation Index (NDVI) were calculated using image interpreting and supervised classification technique by remote sensing software ERDAS image 8.4. The relation model between urban underlying surface temperature (UUST) and urban air temperature was setup according to the certain correlation pattern. Reference to the relational standard of assessing human comfort and other meteorology data of Hangzhou City in summer, the spatial distribution characteristic and the spatial variation degree of human comfort of heat environmental quality are estimated and mapped on a middle scale, that is, in six districts of Hangzhou City. Then the paper reveals the main characteristic of spatial variation from 1991 to 1999. Lastly, the change mechanism is analyzed and discussed from the viewpoint of city planning, construction and environmental protection° KEY WORDS: urban heat environmental quality (UHEQ); remote sensing ; Geographic Information System ( GIS); spatial distribution; variation mechanism CLC number: TP79; P407 Document code: A

Analysis of Urban Growth and Sprawl from Remote Sensing Data

“…Several studies have addressed these issues with or without the consideration of demographic process and urbanisation which have dealt with diverse range of themes (e.g., Acioly and Davidson 1996;Wang et al 2003;Páez and Scott 2004;Zhu et al 2006;Belkina 2007;Puliafito 2007;Yanos 2007;Martinuzzi et al 2007;Hedblom and Soderstrom 2008;Zhang and Atkinson 2008;Geymen and Baz 2008). Several studies have addressed these issues with or without the consideration of demographic process and urbanisation which have dealt with diverse range of themes (e.g., Acioly and Davidson 1996;Wang et al 2003;Páez and Scott 2004;Zhu et al 2006;Belkina 2007;Puliafito 2007;Yanos 2007;Martinuzzi et al 2007;Hedblom and Soderstrom 2008;Zhang and Atkinson 2008;Geymen and Baz 2008).…”

“…Positive correlation between land surface temperature and impervious surface clearly indicates temperature increase in the sprawled area Wang et al 2003). On warm days, urban areas can be 6-8 • F (3.5-4.5 • C) warmer than surrounding areas, an effect known as an urban heat island (Frumkin 2002) (Fig.…”

Advances in remote sensing applications for urban sustainability

“…6. A positive correlation has been deduced between impervious surfaces and land surface temperature (LST) in the sprawled areas [87,90], where impervious surface areas become warmer than the surrounding areas. Two main factors cause the UHI effect.…”

“…The latter is a critical factor for urban stakeholders as unplanned urban growth can have a long-term negative impact on urban sustainability on a range of scales-local, regional, national, and potentially inter-governmental [75]. Impacts include detrimental economic consequences such as the reduction in the productivity of key economic sectors [18]; environmental degradation such as poor air quality, and increased urban temperatures and surface run-off [53,85,87]; and negative societal impacts such as increased morbidity and mortality, negative impacts on quality of life, and the fragmentation of neighbourhoods and related communities [29].…”

Differences and Causal Mechanisms in the Lithospheric Thermal Structures in the Cratons in East China: Implications for Their Geothermal Resource Potential

“…The Jianghan Basin (JHB) in the Central Yangtze Craton reveals a geothermal heat flow value of 52 mW•m −2 and a thermal lithospheric thickness of 100-160 km [32,33]. The North Jiangsu Basin (NJSB) in the Lower Yangtze Craton boasts an average heat flow value of 67 mW•m −2 , with a thermal lithospheric thickness of 78-85 km [22,34,35]. However, the majority of these studies lack a cohesive framework and do not analyze the geothermal genesis of cratons in East China.…”