Comparative Analysis of Thermal Environments in New York City and Kuwait City

Satellite-derived thermal information over urban areas offers and attractive and inexpensive method which have been utilized in diverse studies including land cover classification, energy flux interactions, and as input for models of urban surface atmosphere exchange. In this study, we utilize Landsat ETM+ imagery to analyze the dependence of energy fluxes on the urban surface properties in York City and Kuwait City, located in temperate and arid environments, respectively. Thermal imagery is used in conjunction with multispectral imagery to interpret the distribution of surface temperatures in the context of vegetation endmember abundances estimated by spectral mixture analysis. In general, the surface temperatures observed for the surrounding desert areas in Kuwait City are higher than the built-up areas. However, in New York City the suburban areas with more vegetation have relatively lower temperatures than the residential and commercial areas. Even though Kuwait City has lower vegetation fractions, the cooling effect is apparent and is clearly defined in the residential areas. Scatterplots of surface temperature and vegetation fractions define the physical limits imposed by the vegetation cover, soil water content, and different combinations of surface materials in each city. More land cover categories are identified in the New York City than the Kuwait City imagery primarily due to the morphology and location of the two cities.