Aufeis is a recurring natural phenomenon in Ulaanbaatar, Mongolia, that significantly affects local communities and urban infrastructure during winter. Despite its annual occurrence, the processes and natural factors influencing aufeis formation remain poorly understood. This study investigates the long-term dynamics of aufeis formation and the natural factors controlling its extent and distribution. Landsat satellite imagery from 2009 to 2024 was analyzed to assess multiyear changes in aufeis extent, and drone imagery was employed to map the monthly dynamic changes in aufeis during the winter of 2023-2024. The results show that aufeis typically forms in November, reaches a peak in March, and completely melts by May. Over the past 14 years, aufeis areas ranged from 0.01 km 2 to 0.03 km 2 . However, in the winter of 2023-2024, the aufeis expanded to 0.04 km 2 , with significant encroachment into settlement areas, causing notable damage. This shift in spatial distribution is attributable to changes in ground surface temperature induced by thick snow cover that functioned as thermal insulation and allowed spring water to flow beneath the snow and accumulate in low-lying areas. Furthermore, variations in annual precipitation and geological conditions influenced the extent of aufeis.

Published Date:2025-07-01