Quantitative approach for monitoring the urban heat island effects, using hyperspectral remote sensing

The data acquired over an inner semiarid city in Israel, using the DAIS-7915 hyperspectral sensor were processed to yield thermal-based maps. This was done in order to assess the distribution effect of the urban heat island (UHI) in a non traditionally way (thermal fluxes and related properties instead of surface and air temperatures information). In this study, a spectral-based approach was used to process data from the DAIS sensor to yield diverse thermal parameters over Afula city, Israel. The DAIS sensor consists of 79 bands across the VIS-NIR-SWIR-TIR spectral region. Seven bands across the TIR region permit the extraction of parameters such as emissivity and energy fluxes on a pixel-by-pixel basis using the information from the VIS-NIR-SWIR region. Following R. Richter's (1996) steps we used the DAIS data in conjunction with ground data taken at the time of the overpass to obtain spatial thermal recognition of the selected city. Comparing the results to the traditional UHI map (air and surface temperature) shows that the spectral-based maps provide additional information about the UHI that cannot be extracted in the traditional way.