Examples

File → Examples loads one of four built-in projects. They are small and run in seconds.

Infiltration & evaporation with roots

A 100 cm profile (101 nodes) of loam (0–50 cm) over sand, with the van Genuchten parameters of Carsel and Parrish (1988). Atmospheric boundary condition with runoff at the surface, free drainage at the bottom, six records of rain (3 cm/d in the first 2 days, 8 cm/d between days 8 and 12), potential evaporation and transpiration over 30 days. Roots in the upper 30 cm with the Feddes stress function Feddes et al. (1978). Observation nodes at 20, 50 and 100 cm. This project is loaded at start (getting started).

Solute pulse with sorption and decay

Steady infiltration of 2 cm/d into a 100 cm loam column (201 nodes). A tracer with a concentration of 10 is applied for 10 days with a concentration-flux boundary condition; linear sorption (Kd = 0.2 cm³/g, bulk density 1.3 g/cm³), first-order decay in the liquid and the solid phase (0.01 1/d), dispersivity 2 cm. Shows the solute pages and the breakthrough at the observation nodes (solute transport).

Parameter estimation: one-step outflow

A 10 cm soil core drains against a suction of 100 cm applied at the bottom (time unit hours). α, n and Ks are estimated from the cumulative outflow at 11 times and one retention point. The data were produced with θr 0.08, θs 0.40, α 0.025 1/cm, n 1.7, Ks 3 cm/h, l 0.5 and rounded; the initial estimates are off by 20–70 %. Run starts the estimation (parameter estimation, results).

Parameter estimation: soil temperature

Heat transport in a 1 m loam profile wetted by an infiltration of 2 cm/d; the surface temperature oscillates daily by ±8 °C around 15 °C. The coefficient b1 of the thermal conductivity and the heat capacity Cn of the solid phase are estimated from temperatures at 5, 10 and 20 cm over 5 days. The data were produced with the loam values of the HYDRUS examples and rounded to 0.001 °C; the initial estimates are off by +25 % and −20 % (heat transport).

HYDRUS-1D examples

The examples of the HYDRUS-1D distribution (Examples/Direct and Examples/Inverse of a HYDRUS-1D installation) can be opened directly (HYDRUS-1D projects); they are part of the test suite of Rusteau (relation to HYDRUS-1D).

Literature cited in this topic

• Carsel, R. F., and R. S. Parrish (1988). Developing joint probability distributions of soil water retention characteristics. Water Resources Research 24(5): 755–769. doi:10.1029/WR024i005p00755
• Feddes, R. A., P. J. Kowalik, and H. Zaradny (1978). Simulation of Field Water Use and Crop Yield. Simulation Monographs, Pudoc, Wageningen, 189 pp.

All sources: References.