Study On Urban Heat Island And Its Influence In Beijing City Base On TM Images

With the growing of cities size, urban heat island has become an important environmental issues in urban development. Which seriously influence natural environment and human life, and which has brought economic loss to society. Research on urban heat island is significant to alleviate the hazards, reduce socio-economic loss. Urban heat island has wide impact, plant phenology is one of the sensitive parameters of ecosystem changes in deciduous broad-leaved forest, study on impact of urban heat island on plant phenology provide reference to study on impact of future global warming on ecosystem.This research is based on Landsat TM data, extract the brightness temperature, NDVI and NDBI, relationships between urban heat island effect and vegetation and buildings were studied with the method of characteristic profile extraction. Research on impact of urban heat island effect target on plant phenology, with method of remote sensing combined with ground surveys and GIS analysis, quantitative research impact of urban heat island effect on plant phenology, eventually establish the influence model of urban heat island effect on plant phenology (the ground field survey data) in spring. Conclusions are as follows:(1) Plant phenology, urban heat island effect, vegetation index and the building index of Beijing have obvious regional difference. (2) Urban heat island effect and building have a positive correlation; (3) Vegetation can effectively absorb heat, reducing temperature with photosynthesis, transpiration, there is a negative correlation between vegetation index with urban heat island in summer, but there is a positive correlation between vegetation index with urban heat island effect, vegetation in the higher temperature area earlier meet accumulated temperature threshold than vegetation in the lower temperature area; (4) The less distance between the other profiles and the central profile is, the stronger the negative correlation between brightness temperature and NDVI is, the stronger the positive correlation between brightness temperature and NDBI is; (5) The relationship between brightness temperature and NDBI, brightness temperature and NDVI is affected by the complexity of land use structures.(6) There was a positive correlation between urban heat island effect with the plant phenology, the coefficient of response model is 0.3165.This paper study the relationships between urban heat island effect and vegetation and buildings, and first quantitative research on the relationship between plant phenology with urban heat island in Beijing, revealed the effect mechanism, which provides a reference for the future planning of urban construction of Beijing, green space planning and economy development.