Modelling capillary hysteresis effects on preferential flow through melting and cold layered snowpacks

摘要: Abstract Accurate estimation of the amount and timing water flux through melting snowpacks is important for runoff prediction in cold regions. Most existing snowmelt models only account one-dimensional matrix flow neglect to simulate formation preferential paths. Consideration lateral flows has proven critical improve performance soil groundwater porous media models. A two-dimensional physically-based snowpack model that simulates snowmelt, refreezing meltwater, heat flows, paths presented. The assumes thermal equilibrium between solid liquid phases uses recent snow physics advances estimate hydraulic properties. For first time, capillary hysteresis accounted a model. finite volume method applied solve 2D coupled mass transfer equations. with provided better simulations suction at wet dry interface wetting sample than did boundary drying curve. Capillary also improved path dynamics discharge hydrograph. Simulating subfreezing allowed generate ice layers, increased vertical exchange energy, thus modelling faster warming would be possible without flow. capable simulating many attributes heterogeneous natural snowpacks. These features not qualitatively simulations, but understanding processes both level sloping terrain, illuminate how uncertainty snowmelt-derived calculations might reduced inclusion more realistic