The Dynamics of Anthropogenic Snow Patch Melting and Assessment of Pollution in Meltwater

Annually, more than 1500 × 103 m3 of snow are collected and transported from Yuzhno-Sakhalinsk territory. This volume of snow is stored at two sites, where it melts naturally over the warm seasons. The resultant meltwater flows unregulated into the urban environment. As a consequence, flooding of urban infrastructure objects and increased environmental stress across the city’s territory ensue. This work presents actual volumes of melting recorded for the period 2018–2022, combining remote sensing techniques and ground-based measurements. These observed volumes are compared against results simulated using four different methods, among which the ETI model proved most effective, yielding the smallest error relative to actual annual snowmelt volumes. Additionally, an empirical snowmelt model based on observational data is proposed, offering potential utility for flood risk assessment and contaminant transport modeling. In 2018 and 2019, meltwater samples were collected at the beginning and end of the snowmelt period from snow storage sites. Heavy metal content (V, Cr, Cu, Zn, Cd, Pb) was measured in these samples. The highest concentrations were found at the onset of the snowmelt period (June), declining noticeably toward its conclusion (August). Using calculated snowmelt volumes and pollutant concentrations, the mass load of pollutants was assessed. A significant imbalance in major cations and anions typical of natural waters was detected in the snow storage sites meltwater, characterized by elevated levels of chloride ions (Cl–) and sodium ions (Na+). This indicates substantial impact from anti-skid agents used throughout the city, which accumulate on snow storage sites following snow removal operations.