Remote Sensing Study On The Anthropogenic Heat Discharge In The City Of Fuzhou

The increase bettween local atmospheric and surface temperatures in urban areas compared to the surrounding rural areas intensifies the condition of urban thermal environment. The effect is due primarily to the concentration of human activities and artificial land surface changes. Contrasting the temperature between urban areas and rural areas is a directional method to analyse thermal environment, which is not a quantitative analytical means.To study thermal environment condition quantitatively, we research spatial-temporal distribution and change characteristics of impervious surface area, surface temperature and heat fluxes.In this study, satellite remote sensing (Landsat TM and ETM+images acquired in1989and2001) are used to extract the land surface temperature, albedo and fractional vegetation cover. We use a model of linear spectral mixture to abstract impervious surface area of Fuzhou city. Then the sensible and latent heat fluxes which are climatic factor related to the urban heat island can be estimated with local ground meteorological data. Fractional vegetation cover (FVC,0-100%) was used to improve the calculation of the latent heat flux in impervious surface areas covered with anthropogenic building or cement road, and it improves the method calculating the latent flux of impervious surface area (ISA). Based on a heat-balance model, anthropogenic heat discharge in sensible heat flux is separated. In the end, by assessing and validating the accuracy of surface heat fluxes, we demonstrate that the estimated results of heat fluxes in our study are reasonable.After estimating all factors including the net radiation, the ground heat flux, the sensible heat flux and the latent heat flux and the anthropogenic heat discharge of heat-balance model, we analyze the variance of these factors in different Land Use/Land Cover (LULC) categories in urban and peripheral areas. In our study, one research focus is the relationship between anthropogenic heat discharge increasing the temperature of land surface as with the sensible heat flux and percent ISA. Another research focus is how the anthropogenic heat discharge influences the distribution of surface temperature.We make three conclusions in this paper. In the urban areas and surrounding areas, the factors of heat-balance model exerts distributing characteristies along with LUCC. In the subtropical climate of Fuzhou, the seasonal disparities of anthropogenic heat discharge between early spring and early summer energy consumption vary little. Anthropogenic heating is influenced by urban expansion, land use and lifestyle changes with implications for energy consumption. Anthropogenic heat discharge playes a important role causing the rise of land-surface temperature, and the strength is impacted by seasonal variation.