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Estimation of the Philip Infiltration Parameters from Rainfall Simulation Data
Author(s) -
Bach L. B.,
Wierenga P. J.,
Ward T. J.
Publication year - 1986
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/sssaj1986.03615995005000050047x
Subject(s) - sorptivity , infiltration (hvac) , hydraulic conductivity , soil science , mathematics , regression analysis , statistics , hydrology (agriculture) , soil water , environmental science , geotechnical engineering , physics , geology , meteorology , porosity
A new, simple technique for estimating the parameters of the two‐term Philip infiltration equation was developed and tested using field‐measured data obtained in the northern Chihuahuan desert of New Mexico. The technique simultaneously provided information on the relationship between the Philip equation parameter A , and the field‐measured hydraulic conductivity. The equation was reformulated as I − cK f = 1/2 St −1/2 , where I is the infiltration rate, S the sorptivity, t the time, K f the field‐measured final infiltration rate, and c , a coefficient relating K f to the Philip parameter A . The final, steady infiltration rate measured in the field was used for the value of K f . Regressions of ( I − cK f ) vs. (1/2 t −1/2 ) for values of c between 0 to 1 resulted in optimum c values for each treatment along with their corresponding S values. For the soils in this area, values for the coefficient c were sometimes outside the suggested range of 0.33 to 0.67, and were different for each study site. The regression analysis also showed that the value of S can be highly sensitive to changes in c . Using the values of S and c determined by the proposed method, a comparison was made between computed infiltration rates and measured infiltration rates. The results of this study showed that the prediction method provided adequate fits to field‐measured data, and that the choice of an appropriate c factor is important in determining infiltration parameters from field data.