Calculation of Water Retention Curves of Rock Samples by Differential Evolution

The water retention curve has a key role for the hydraulic characterization of porous media. Its experimental determination requires the accurate and detailed measurement of the matric potential and water content from saturation to oven dryness. The experimental data are fitted with a parametric model to calculate the analytic curve describing the hydraulic properties of the sample. We present a new method, based on differential evolution, for the determination of the characteristic parameters of the water retention models. This method allows to reduce the number of measurements necessary for obtaining accurate model parameters, decreasing the time needed to adequately characterize the sample. The method is applied to the calculation of water retention curves of sedimentary carbonatic rock of marine origin.