Permafrost soil water content evaluation using high-frequency ground-penetrating radar in Amdo catchment, Central Tibetan Plateau

High-frequency ground-penetrating radar (GPR) was applied to assess soil water content spatially during the freezing periods at a continuous permafrost site in Amdo catchment, which is centrally located in Tibetan Plateau. The active layer thickness was also roughly presented through the whole survey, which traveled almost 15Km from the top of a hill towards a seasonal stream. The results revealed that average soil moisture increased slightly towards the down-slope direction and kept a higher level near the stream, especially in the deeper layers. Moreover, we found that active layer depth varied with topography, and it ranged from 1.92m to 2.44m along the profile. The topography (i.e. slope and elevation) and stream distribution significantly alter spatial pattern of soil moisture and active layer thickness in the study regions.