Estimating Soil Hydraulic Parameters during Ponding Infiltration Using a Hybrid Algorithm

Accurate inversion of soil hydraulic parameters based on the van Genuchten–Mualem model has received much attention in science research. Herein, a hybrid algorithm method using particle swarm optimization and vector-evaluated genetic was used to invert θs, α, n, Ks, with objective functions infiltration rate, cumulative infiltration, water content. Then, numerical experiments were conducted four typical soils at three initial content levels (20, 40, 60% effective saturation) verify accuracy inverse method. The results showed that inversed retention conductivity curves approximately same as real curves, root mean square errors 0.00101–0.00192 cm3·cm−3, 0.00800–0.02519 respectively, both Nash-Sutcliffe coefficients 1.0. Additionally, laboratory also performed compare for verification, within small squared 1.0 Nash–Sutcliffe coefficients. Furthermore, can achieve acceptably accurate parameter even substantial measurement included content, final Thus, is robust found be practical field experiments.