Estimation of permafrost ice reserves in the source area of the Yellow River using landform classification

Ground ice is a distinguishing characteristic of permafrost soil.As permafrost profoundly influences the hydrology, ecology and engineering design in cold regions, it is important to accurately estimate the underground ice reserves of permafrost.Thus, this study investigated landforms and their genetic types in the source area of the Yellow River.The lithologic composition and water content were analyzed using field data from 105 boreholes.The underground ice reserves at depths of 3.0-10.0 m were estimated in the source area of the Yellow River.This research also focused on the spatial distribution of shallow underground ice.The results show that ① the total amount of ice reserves at depths between 3.0 and 10.0 m was approximately (49.62±17.95) km³ and the ice reserve per unit was (0.293±0.107) m³; ② in the horizontal direction, high ice contents were associated with lacustrine-marshland plain and periglacial hill landforms, while low ice contents correlated with erosional platform and alluvial-proluvial plain landforms; and ③ in the vertical direction, high ice contents were observed close to the upper limits of permafrost and gradually decreased with depth.