Application of In-situ Lysimetric Studies for Determining Soil Hydraulic Conductivity

Several techniques such as laboratory column studies, under normal and accelerated gravity environments, numerical modeling and pedo-transfer functions have been employed by previous researchers to determine hydraulic conductivity of soils. However, these methods suffer with several limitations, particularly, as far as regeneration of in-situ soil conditions and boundary conditions, in an exceptionally small model, are concerned. Under these circumstances, in-situ lysimeters are found to be quite useful for conducting the investigations to obtain hydraulic conductivity of fully saturated or partially saturated soils. These lysimeters can easily be installed in the soil mass, without disturbing its state, and are large enough to exhibit representative soil mass that exist at the site. With this in view, an attempt was made in this study to determine hydraulic conductivity of the soil mass beneath a waste disposal site in India by installing a lysimeter. Details of the instrumentation are presented in this paper along with the methodology to determine hydraulic conductivity of the soil mass.