Advances in the Study of Preferential Flow and Its Transport Pathways Characteristics in Strongly Permeable Soil Strata

Soil preferential flow refers to the rapid transport of water and solutes through heterogeneous pathways within the soil matrix, particularly in highly permeable formations. This process exerts a significant influence on groundwater recharge and contaminant diffusion. Under the global One Health framework, characterizing soil preferential flow and its transport channel characteristics is crucial for the exchange between soil and groundwater, which is becoming increasingly vital for the health of the soil-groundwater system. We systematically review research progress on soil preferential flow and its transport channel characteristics in highly permeable formations, utilizing publications from the Web of Science (WOS) and China National Knowledge Infrastructure (CNKI) databases analyzed with CiteSpace. Research hotspots primarily focus on “numerical simulation”, “dye tracing”, and “solute transport”, emphasizing improvements in soil structure analysis, experimental methodologies, and the impact on contaminant diffusion. Among existing techniques, Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) demonstrate significant advantages in the high-resolution identification of preferential flow pathways, enabling detailed characterization of internal soil structures. However, challenges such as complex data interpretation persist in large-scale field applications. In environmental modeling, numerical models like HYDRUS, SWMS-2D/3D, MT3DMS, and MODFLOW-CFP are widely employed. Nevertheless, dynamic field monitoring technologies for large-scale field remain inadequate, a coordinated multitechnique monitoring framework is yet to be established, and model parameter optimization continues to present challenges. Under the One Health framework and within global climate change, further investigation into the impact of preferential flow on the hydrological processes of the soil-groundwater system is imperative. This will advance the precise characterization of preferential flow and its transport channel characteristics in highly permeable formations, fostering deeper research into water resource management and pollution prevention within the soil-groundwater system.