EVALUATION OF SPATIAL DISTRIBUTION OF HYDRAULIC CONDUCTIVITY USING EFFECTIVE POROSITY DATA

The use of spatial distribution of effective porosity (Φε) to estimate the distribution of saturated hydraulic conductivity (K2) is evaluated on five new soils and on a combination of soils. The K2 is related to Φε by a generalized Kozeny-Carman equation. This equation is then combined with scaling theory to derive the frequency distribution of K2 scaling factors from Φ distribution. The results of fractile diagrams and variances show that the use of the generalized Kozeny-Carman equation, with exponent taken equal to 4 or 5, gives, overall, good estimates of the distribution of K2 scaling factors from Φε measurements. The exponent value of 4 is more generally applicable. It is interesting to find that the above method applies as well across soil types, i.e., when the data of different soils are combined. The empirical equation for combined soils may also be used directly to estimate mean K2 over an area, as a first-order approximation.