[Multi-gradients of land surface temperature in mountainous cities with rapid urbanization: a case study in central area of Chongqing City].

By using TM/ETM+ and MODIS images, the land surface temperature (LST) and relative heat island intensity (RHII) of the central area of Chongqing City were extracted to analyze the distribution patterns of the LST and RHII along the multi-gradients of topography, population, and gross domestic product (GDP) as well as the potential quantitative relationships. The LST and RHII manifested a non-monotonically decreasing trend along the gradients of elevation and relief degree, respectively, both with a significant quadratic polynomial relationship. The maximum RHII appeared at 200-350 m elevation section due to the massive urban construction activities, and had significant linear relationships with the population density and the GDP per square kilometer. The RHII rose about 0.10 degrees C when the population density increased 1000 people per square kilometer, and rose about 0.08 degrees C when the GDP per square kilometer increased 10 million RMB Yuan.