The study of variations in groundwater occurrence influencing the migration characteristics of LNAPL

LNAPL (Light Non-Aqueous Phase Liquid) contamination has consistently attracted attention, and understanding its migration characteristics can provide valuable insights for remediating soil pollution.This study employs a combination of Electrical Resistivity Tomography (ERT) and direct observation to investigate the migration mechanisms and rates of LNAPL under three conditions: unsaturated media, constant groundwater level, and declining groundwater level.The findings indicate that groundwater is a crucial factor influencing the migration of LNAPL.Under unsaturated media conditions, the initial migration rate is the fastest. In the presence of a constant water level, the average migration rate is the slowest, exhibiting a linear decreasing trend. The migration is fastest during declining groundwater levels, and under the influence of three-phase coupling, LNAPL migration rates oscillate.The use of ERT can meet the observational accuracy at the laboratory scale, enabling the visualization of the migration process of LNAPL within the subsurface medium.