Characterizations of the water retention curve of the dry-cold snowpack

The water retention curve (WRC) has been widely used to quantify moisture transport characteristics of maritime snowpack. However, there is a notable deficiency in experimental studies focused on the WRC of dry-cold snowpack in continental climate conditions. This study selected dry-cold snowpack samples with five densities to measure the variations in volumetric water content using the pressure plate method. The Van Genuchten (VG) and Brooks-Corey (BC) models were then used to fit the snowpack WRCs, aiming to investigate their applicability to dry-cold snowpack and explore the relationship between the model parameters and snowpack characteristics. The results indicated that: (1) Compared to the particle size and the ratio of snowpack density to particle size, the snowpack density shows a higher correlation with the shape parameters of VG model and BC model; (2) There is a nonlinear relationship between the snowpack density and the shape parameters of VG model and BC model; (3) Both the BC and VG models provide a high level of accuracy in fitting the experimental data, with the BC model showing slightly better precision. However, after regression correction, the VG model outperforms the BC model. The findings provide support for in-depth studies of moisture movement characteristics in different types of snow, and have significantly practical value for improving the accuracy of early warning systems for hazards such as avalanches and floods.