Testing a Simplified Approach to Determine Field Saturated Soil Hydraulic Conductivity

Interpreting and simulating hydrological processes need a large number of field saturated soil hydraulic conductivity, K-fs, data that should be collected with simple and rapid field experiments. A Simplified method based on a Beerkan Infiltration run (SBI method) was recently developed and tested successfully on Burundian soils. With the SBI method, a cylinder is inserted to a short depth into the soil and the infiltration time of a few small volumes of water repeatedly applied at the surface of the confined soil is measured. Calculating K-fs needs the slope of the linearized cumulative infiltration vs. time relationship and an estimate of the so called alpha* parameter. In this investigation, the SBI method was validated with reference to a larger dataset, also including different Sicilian soils. The alpha* value of first approximation (0.012 mm(-1)) yielded an estimate of K-fs differing in general by not more than a factor of three from the K-fs values obtained by the more complete and onerous BEST (Beerkan Estimation of Soil Transfer parameters) procedure of soil hydraulic characterization. The K-fs values obtained with SBI method were also very close (means differing by a factor of 1.01) to the ones determined with the One Ponding Depth relationship for the single ring pressure infiltrometer technique. Detection of physically plausible relationships between alpha* and the slope of the linearized infiltration curve indicated that the measured infiltration process contains the necessary information to estimate alpha*. Different alpha* predictive relationships for Sicily and Burundi allowed to obtain estimates of K-fs never differing by more than a factor of three from the corresponding values obtained with BEST. The developed method is a good candidate method for intensively sampling an area of interest. Points needing developments include tests with other datasets, comparisons with independent measurements of both alpha* and K-fs, and maybe development of an improved experimental methodology to obtain the infiltration data. (C) 2013 The Authors. Published by Elsevier B.V.