Abstract: Under the effects of climate warming, the freezing, thawing, and their durations of seasonal frozen soil changed greatly. By using the 1971-2005 observation data collected from eight weather stations in east Gansu, the effects of climate change in east Gansu on the seasonal frozen soil of this region were studied. The results showed that since 1970s, the wintertime air temperature of this region raised by 2.7 ℃, freezing and thawing dates of soil in a thickness of 30 cm shifted 10 days later and earlier, respectively, freezing duration shortened by about 20 days, and the maximum frozen depth decreased by about 20 cm. With persistent climate warming, the maximum frozen depth would be decreased continuously, and it was predicted that in 2050, the decrement would be at least about 15 cm, which would have greater effects on the design and construction of engineering.

Key words: Copper tailings yard, Heavy metal, Contamination, Accumulation, Paeonia ostii