FIELD DETERMINATION OF SORPTIVITY AS A FUNCTION OF WATER-CONTENT USING A TENSION INFILTROMETER

Sorptivity for tension wetting in the field was determined and weighte d-mean diffusivity calculated. Both tension sorptivity and weighted-me an diffusivity could be described by an exponential function of the fo rm aexp(btheta) where theta is either mean water content or dimensionl ess water content and a and b are parameters. This relation was valid for an initial water content between 0.016 and 0.047 m3m-3 and a final water content between 0.154 and 0.316m3m-3. Tension sorptivity was mo re strongly correlated with average water content than dimensionless w ater content. However, in the case of weighted-mean diffusivity, the c orrelations with both dimensionless water content and average water co ntent were almost the same.