Spatial Averaging of van Genuchten Hydraulic Parameters for Steady‐State Flow in Heterogeneous Soils: A Numerical Study

• DOI: 10.2136/vzj2002.2610
• Publication Date: 2013-10-02T18:39:00Z
• Authors: Jianting Zhu; Binayak P. Mohanty
• Keywords: Infiltration (HVAC); Soil texture; Pedotransfer function

For meso‐ or regional‐scale Soil–Vegetation–Atmosphere Transfer (SVAT) schemes in hydroclimatic models, pixel dimensions may range from several hundred square meters to kilometers. Pixel‐scale soil hydraulic parameters and their accuracy are critical for the success of hydrologic models. This study tries answer a major question: What will be effective average properties entire (or footprint remote sensor) consisting textures if can estimated each individual texture? In this study, we examined impact areal heterogeneity on ensemble behavior steady‐state evaporation infiltration. Using widely used van Genuchten model parameter statistics obtained neural network–based pedotransfer functions (PTFs) various textural classes, address property uncertainty vertical flow large‐scale heterogeneous fields. The averaging compared with “effective parameters” calculated by conceptualizing areally formation as an equivalent homogeneous medium that discharge approximately same amount flux soil. boundary conditions correlation parameters, well investigated discussed. light our results, suggest following guidelines averaging: arithmetic means K s n , value between geometric α when highly correlated, harmonic poorly correlated.