甘肃陇东地区季节冻土变化对气候变暖的响应

Effects of climate warming on seasonal frozen soil in east Gansu

受气候变暖的影响,季节冻土的冻结、融化及持续时间都发生了较大变化。运用陇东地区8个气象站1971—2005年温度、冻土观测资料,分析了该地气候变化对季节冻土的影响。结果表明:自20世纪70年代以来,该地冬季气温升高了2.7℃,30cm的冻土冻结时间大约推后了10d,冻土融化时间提前了10d,冻土持续时间缩短了20d左右;35年来平均最大冻结深度减少了约20cm;随着气候的持续变暖,最大冻土深度将进一步减少,预计2050年至少比现在减少15cm左右,对未来建设工程的设计及施工有较大影响。

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.