Premium
Climate, soil, and vegetation: 3. A simplified model of soil moisture movement in the liquid phase
Author(s) -
Eagleson Peter S.
Publication year - 1978
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr014i005p00722
Subject(s) - infiltration (hvac) , water content , water table , environmental science , soil science , hydrology (agriculture) , moisture , capillary fringe , groundwater , evapotranspiration , soil water , geology , vadose zone , geotechnical engineering , meteorology , geography , ecology , biology
Natural soil systems are modeled one dimensionally from the surface to a stationary water table by a homogeneous medium defined by three independent parameters. Four varieties of soil moisture movement are analyzed separately, and their effects are linearly superimposed. Infiltration and exfiltration are described by the Philip equation, which assumes the medium to be effectively semiinfinite and the internal soil moisture at the beginning of each storm and interstorm period is assumed to be uniform at its long‐term space‐time average. The exfiltration equation is modified for the presence of natural vegetation through the approximate introduction of a distributed sink representing the moisture extraction by plant roots. Gravitational percolation to groundwater is assumed to be steady throughout the rainy season at a rate determined by the long‐term space‐time average soil moisture. Capillary rise from the water table is assumed to be steady throughout the year and to take place to a dry surface.