Transient Response of Upland Watersheds to Storm Events

摘要

Field observations of pore pressure responses to rain events at two diverseexperimental watersheds further reflect the importance of heterogeneous soil and geologic materials as they affect storm runoff responses. An existing physically-based numerical subsurafce flow model was modified to incorporate infiltration partitioning and overland flow. Through a series of parametric simulations, this model was used to study storm runoff processes and pore pressure evolution in hypothetical hillslopes as affected by: non-linearities in the conductive and storage properties of soils and bedrock: hillslope geometry; downstream (stream side) boundary conditions; and antecedent moisture conditions. Rainfall rates of 1-year return interval magnitude were applied to convexoconcave slopes and subsurface storm flow was observed to be the predominant runoff generation process for the soil types considered.