DETECTION OF METEOROLOGICAL STATIONS' UNDERLYING SURFACE CHANGE BASED ON RS AND ANALYSIS OF ITS INFLUENCE ON AIR TEMPERATURE CHANGE IN CHINA

Urban expansion has been the dominant characteristics in land use and land cover change in recent decades in China. Meteorological stations' observation environments are affected by urban heat island effect due to urban expansion, which leads to overestimation in the records of air temperature and influences the researches based on them. In this study, the underlying surface surrounding 756 meteorological stations across China was identified based on remote sensing images over a number of time intervals to distinguish the rural stations that became urban stations. 608 stations with continuous observation records during 1978 to 2007 are picked out, among which there are 58 urban stations. Annual and seasonal change characteristics of air temperature are analyzed based on these stations' records. It was concluded that the change rate of urban stations' annual mean air temperature is higher than the others' especially the minimum air temperature. The difference in air temperature of urban stations reduces more due to the minimum air temperature's greater rise. Air temperature in winter, spring and autumn show more apparent rising trend than in summer