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Solution of a nonlinear absorption model of mixed saturated‐unsaturated flow
Author(s) -
Broadbridge P.
Publication year - 1990
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/wr026i010p02435
Subject(s) - sorptivity , ponding , soil water , dimensionless quantity , nonlinear system , soil science , hydraulic conductivity , water content , geotechnical engineering , water flow , environmental science , mathematics , mechanics , geology , physics , porosity , drainage , ecology , quantum mechanics , biology
A nonlinear diffusion model of Fujita is adapted to solve a mixed saturated‐unsaturated flow problem representing absorption of water by a soil with a constant pond depth at the surface. From the closed‐form solution, there emerges an equation relating dimensionless sorptivity, dimensionless pond depth, and a single soil hydraulic nonlinearity parameter. For the whole range of soil types, the ratio of ponded sorptivity to unponded sorptivity increases significantly with pond depth but the ponding effect is stronger in weakly nonlinear soils than in highly nonlinear soils. In weakly nonlinear soils the ponding effect is greatly enhanced by increasing the initial water content, but in extremely nonlinear soils the initial water content has little influence.