Application of airborne time-domain electromagnetic method in investigation of permafrost
Investigating the spatial distribution of permafrost is critical for cryosphere research.At present,China's investigation con-cerning 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 deter-mined by borehole temperature measurements.This suggests that the TDAEM method exhibits high effectiveness and accuracy in per-mafrost 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.