Nowadays, more than 40% of the population lives in Chinese cities. The rapid urbanization process brought about many ecoenvironmental problems, such as the drastic change of land use and development of urban heat island. Three Landsat TM and ETM+ images data of Beijing acquired on April 9, 1995 and April 30, 2000 were selected to this research. The land surface temperature (LST) and land use and land cover (LULC) classes were retrieved and extracted. The temperature-vegetation index (TVX) space was constructed to investigate the influence of land changes over LST. The result showed that the land use change was an important driver for LST increase, the temporal trajectory of pixels in the TVX space migrated from the dense-vegetationlow temperature condition to the sparse vegetation-high temperature condition

Rice is a staple food by an increasing number of people in China. As more issues have arisen in China due to rice contaminated by cadmium (Cd), Cd contamination in arable soils has become a severe problem. In China, many studies have examined Cd contamination in arable soils on a national scale, but little studies have focused on the distribution of Cd in paddy fields. This study explored the spatial pattern of Cd in paddy soils in China, made a preliminary evaluation of the potential risk, and identified the most critically contaminated regions based on the domestic rough rice trade flow. The results showed that Cd concentrations in paddy soils in China ranged from 0.01 to 5.50 mg/kg, with a median value of 0.23 mg/kg. On average, the highest Cd concentrations were in Hunan (0.73 mg/kg), Guangxi (0.70 mg/kg), and Sichuan (0.46 mg/kg) provinces. Cd concentrations in paddy soils in central and western regions were higher than those in eastern regions, especially the southeastern coastal regions. Of the administrative regions, Cd standard exceedance rate was 33.2 %, and the heavy pollution rate was 8.6 %. Regarding to Cd of paddy soil, soil environmental quality was better in Northeast China Plain than in Yangtze River Basin and southeastern coastal region. Mining activities were the main anthropogenic pollution source of Cd in Chinese paddy soil. Based on rice trade, more of the Chinese population would be exposed to Cd through intake of rice produced in Hunan province. Certain regions that output rice, especially Hunan province, should be given priority in the management and control of Cd contamination in paddy soil.