基于MODIS卫星遥感的河北省季节性冻土变化特征及其与气温的关系

Variation characteristics of seasonally frozen ground and its relationship with air temperature in Hebei Province based on the MODISS products

近年来,在全球气候变暖的背景下,中国季节冻土最大冻结深度总体呈现减小的趋势。相比于传统的钻孔勘探的方法,卫星遥感技术可以更准确、方便、全面地估算河北省季节性冻土分布及最大冻结深度。利用2002-2022年的遥感地表温度数据,以及1970-2021年的气温数据,采用Stefan公式模拟了河北省季节性冻土最大冻结深度分布及变化规律,并分析了河北省季节性冻土最大冻结深度时空分布特征及其与平均气温的相关性。河北省季节性冻土最大冻结深度总体随海拔高程的降低呈由西北向东南递减的趋势;近50年来,随着气温的升高,河北省季节性冻土最大冻结深度总体呈现减小趋势,平均变化率为-3.60 cm/10 a;季节性冻土的最大冻结深度与平均气温的关系整体呈负相关,中南部及中北部地区的相关性较好,大部分地区的相关系数的绝对值达到了0.55以上;利用卫星遥感数据反演的最大冻结深度可为揭示河北省季节性冻土对气候变化的响应提供参考依据。

In recent years,due to the impact of global warming,the maximum thickness of the seasonally-frozen ground(MTSFG)in China has generally shown a decreasing trend.Compared with traditional borehole exploration methods,satellite remote sensing technology can more accurately,conveniently and comprehensively estimate the distribution and maximum freezing depth of the seasonally-frozen ground in Hebei Province.Based on the remote sensing land surface temperature data from 2002 to 2022 and the air temperature data from 1970 to 2021,the distribution and variation of the MTSFG are simulated by Stefan formula in Hebei Province,the spatial and temporal distribution characteristics of the MTSFG and its correlation with mean air temperature are analyzed.The results show that the MTSFC in Hebei Province decreases from northwest to southeast with the decrease of elevation.In recent 50 years,with the increase of air temperature,the MTSFG in Hebei Province showed a decreasing trend,with an average change rate of-3.60cm/10 a.The relationship between the MTSFG and the average temperature is negative as a whole,the correlation between the central and southern and central northern regions is relatively good,and the absolute value of the correlation coefficient in most areas has reached more than O.55.The MTSFG retrieved using satellite remote sensing data can provide a reference for understanding the response of seasonal frozen soil to climate change in Hebei Province.