时间域航空电磁法在多年冻土调查研究中的应用

Application of airborne time-domain electromagnetic method in investigation of permafrost

多年冻土空间分布调查在冰冻圈研究中具有重要意义。目前国内冻土空间分布调查通常采用地面物探结合测井的探测方法,获得局部点上或线上数据,或者采用不同的遥感模型,模拟估算区域性多年冻土厚度。笔者利用获取的时间域航空电磁数据,根据电阻率计算结果推断多年冻土空间分布特征。推断结果与已知测井资料对比分析表明,根据时间域航空电磁数据反演结果推断的多年冻土层厚度与已知测井测温确定的结果平均误差为18.5%,表明采用时间域航空电磁法开展多年冻土厚度调查是有效的,具有较高的准确性。由于时间域航空电磁测量具有高效、受地形影响小等技术优势,可应用于青藏高原、东北大兴安岭等地区的大面积、快速、定量化的多年冻土调查,为全面调查研究多年冻土空间分布及其对生态环境变化的影响提供新的、有效的技术解决方案。

Investigating the spatial distribution of permafrost is critical for cryosphere research.At present,China's investigation concerning the spatial distribution of permafrost generally employs the detection method of ground geophysical exploration combined with logs to obtain local point or line data.Alternatively,different remote sensing models can be used to simulate and estimate the thickness of regional permafrost.This study inferred the spatial distribution of permafrost based on airborne time-domain electromagnetic(TDAEM)data and resistivity calculation results.The comparative analysis of the inference results and the known drilling data reveals an average error of 18.5%between the permafrost thickness inferred from the inversion results of TDAEM data and the result determined by borehole temperature measurements.This suggests that the TDAEM method exhibits high effectiveness and accuracy in permafrost thickness investigation.With technical advantages like high efficiency and minor topographic influence,the TDAEM method can be applied to the large-scale,rapid,and quantitative permafrost investigation in the Qinghai-Tibet Plateau and the Greater Khingan Range in northeast China.Therefore,this study provides a new and effective technical solution for a comprehensive investigation of the spatial distribution of permafrost and its influence on ecological environment changes.