Monitoring the Interannual Spatiotemporal Changes in the Land Surface Thermal Environment in Both Urban and Rural Regions from 2003 to 2013 in China Based on Remote Sensing

Abstract EN

The thermal environment is closely related to human well-being.

Diurnal and seasonal variations in surface urban heat islands (SUHIs) have been extensively studied.

Nevertheless, interannual changes in SUHIs as well as in land surface temperatures (LSTs) in cities and their corresponding villages remain poorly understood, particularly using data from several continuous years to analyse change rates and corresponding significance levels.

Using Aqua/Terra moderate resolution imaging spectroradiometer (MODIS) data for 2003–2013, we explored not only the interannual changes in annual and seasonal mean LSTs in rural and urban regions which were identified based on modified criteria, but also the SUHI intensities (SUHIIs) for these cities.

The results showed that most of LSTs and SUHIIs did not change significantly (p≥0.05).

Their changes exhibited clear spatiotemporal agglomeration and variation laws.

The rural region LST change rates, which exhibited significant changes, were generally highest in the summer, with most of values of 0.1–0.5°C (yr−1) during the daytime across China, except for the Xinjiang autonomous regions, and 0.1–0.2°C (yr−1) during the night-time.

The rates were lowest in the winter, with most of values of −0.4 to −0.1°C (yr−1).

The rates of daytime SUHIIs with significant changes were generally highest in the summer, with most of values of 0.1–0.3°C (yr−1), and lowest in the winter, even with most of values of −0.4 to −0.1°C (yr−1) in northern central China.

During the night-time, most of rates were 0.0–0.1°C (yr−1).

In China, most of the changes in the surface thermal environment were harmful to humans at both large national and local urban scales.

The changes could lower thermal comfort levels, harm human health, affect human reproduction rates and lives, and increase the energy consumed for refrigeration or heating, thereby increase emissions of greenhouse gases.