Prediction of dynamic hydraulic properties in a ripening soil

The dynamic nature of soil hydraulic behaviour in a physically ripening soil has been predicted. Prediction has been made by relating the degree of physical ripening to parameters of analytical hydraulic functions, thus generating so-called pedotransfer functions. Hydraulic properties have been determined using the standard measurement technique for the moisture retention characteristic, the falling head method for the saturated hydraulic conductivity and the outflow method for both the moisture retention and unsaturated hydraulic conductivity. The estimated parameters in the hydraulic functions, using the inverse approach of the outflow method, were compared with the measured data on the saturated conductivity and the parameters in the analytical function of the van Genuchten model were fitted to the measured data of the moisture retention characteristic. Most parameters estimated from the outflow method are found to be comparable with those of the measured moisture retention and saturated hydraulic conductivity, showing linear relationships with physical ripening. The results of the parameter estimation indicate that soils undergoing physical ripening exhibit a geometric similarity between different ripening stages. The effect of physical ripening on the hydraulic properties mostly appears near the saturation point.