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Optimization of parameters in a model of soil water drainage
Author(s) -
Wall B. H.,
Miller A. J.
Publication year - 1983
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/wr019i006p01565
Subject(s) - water content , soil science , non linear least squares , nonlinear system , hydraulic conductivity , least squares function approximation , drainage , nonlinear regression , moisture , matching (statistics) , soil water , environmental science , mathematics , hydrology (agriculture) , geotechnical engineering , geology , statistics , explained sum of squares , physics , regression analysis , meteorology , ecology , biology , quantum mechanics , estimator
A serious obstacle to widespread application of soil water flow theory to small plots is the difficulty of specifying the moisture characteristics ψ(θ, z ), and conductivity characteristics K (θ, z ), in the face of lateral heterogeneity of these properties. We present a method for the simultaneous determination of effective in situ ψ(θ, z ) and K (θ, z ), given only soil moisture depletion data. The procedure uses a nonlinear least squares fitting routine to find a ψ(θ, z ) which, with its related K (θ, z ), produces calculated fluxes matching those observed. The agreement is an order of magnitude better than that obtained using characteristics determined from laboratory measurements on field samples.