Sensitivity Analysis in Parameter Identification, Test Planning and Test Evaluation Procedures for Two-Phase Flow in Porous Media

The flow model describing unsaturated one dimensional vertical water flow in porous media is given by (1a)$$ \left( {\frac{\partial }{{\partial z}}k(\theta ) \times \left( {\frac{{\partial {h_p}}}{{\partial z}} + 1} \right)} \right) = \frac{{\partial \theta }}{{\partial t}} - {w_0} $$ and (1b)$$ \frac{{\partial \theta }}{{\partial t}} = C({h_0}) \cdot \frac{{\partial {h_p}}}{{\partial t}} $$ where the independent variables are time t and spatial coordinate z, taken positive up-wards. The dependent variables of equation (1) are the water pressure head h_{p =} p_w/ρ_w·g (h_c=-h_p and the water content θ. w₀ is the sink/source term. The capillary capacity function C(h_c) is the first derivative of the hysteretic soil water retention curve. The unsaturated hydraulic conductivity k(θ) depends on the water content in the soil.