Premium
System‐Dependent Boundary Condition for Water Flow from Subsurface Source
Author(s) -
Lazarovitch N.,
Šimůnek J.,
Shani U.
Publication year - 2005
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2005.0046
Subject(s) - infiltration (hvac) , subsurface flow , pressure head , boundary value problem , mechanics , hydraulic head , transient (computer programming) , environmental science , common emitter , inlet , geotechnical engineering , soil science , soil water , geology , materials science , groundwater , engineering , mechanical engineering , mathematics , physics , computer science , geomorphology , mathematical analysis , optoelectronics , composite material , operating system
Infiltration rate of water from a subsurface cavity is affected by many factors, including the pressure in the cavity, its size and geometry, and the hydraulic properties of the surrounding soil. When a predetermined discharge of a subsurface source (e.g., a subsurface emitter) is larger than the soil infiltration capacity, the pressure head in the source outlet increases and becomes positive. The built up pressure may significantly reduce the source discharge rate. The main objective of this work was to develop a boundary condition that describes this process while considering the source characteristics, and to implement this boundary condition into the transient numerical model Hydrus‐2D. This new, system‐dependent boundary condition allows calculation of the source discharge while considering source properties, inlet pressure, and effects of the soil hydraulic properties. The updated numerical model was verified against existing analytical solutions for simplified steady‐state conditions and validated against transient experimental data. Good agreement was found between transient cavity pressures measured in laboratory experiments and those calculated using the updated numerical model. The modified program allows using any analytical model that describes the soil hydraulic properties and source characteristics, simulating both short and long duration infiltration events, as well as considering various geometrical shapes of subsurface sources.