Application of Remote Sensing and GIS to Study Surface Temperature Changes of The Urban Districts in Hanoi during 2005 - 2015 Period
Abstract
Hanoi city has 30 administrative units with area of 3.344,7 km2. High population density leads to fast development of infrastructure and residences, therefore, causing urban “heat island” phenomenon that dramatically affects climate change in Vietnam. Thus, authors used characterized information of bands of satellite image data of Landsat involving 12 urban districts of Hanoi during 3 periods, 2005, 2010, and 2015. With infrared bands, after pixel values were converted from digital number (DN) into energy of Atmosphere spectral radiance, the light surface temperature was determined. However, the real temperature was then determined by adjusting the emissivitty of top cover layer via Normalized Difference Vegetation Index and energy of radiance to top of atmosphere reflectance based on red and near - infrared bands. Combined with urban land situation estimated from image satellite analysis via accreditation classifying method, the correlation regression equation between surface temperature and urbanization speed was proposed.