WASH_1D

WASH_1D solves governing equations (parabolic partial differential equations) for one-dimensional movement of water and solute in soils with the finite difference method.

Model Features

Numerical inversion of hydraulic properties for three methods:
1. Multi-step outflow method (Eching et al.,1993)
2. Evaporation method with tensiometers (Simunek et al., 1998)
3. Evaporation method without tensiometers (Fujimaki and Inoue, 2003)
Optimization of irrigation depth
Simulation of automated irrigation
Simulation of stored volume in a reservoir for automated irrigation NEW!
Soil water retention function: flexible bimodal retention function and modified Shiozawa's function are employed.
Following phenomia are considered:
- Layered soil
- Hysteresis in water retention
- Water vapor movement
- Dependense of albedo on water content
- Root water uptake with a macroscopic root water uptake model
- Plant growth
Therefore, actual evaporation and transpiration rates can be predicted by inputting meteorological conditions

Features of User Interface

Animated display of the result
Combined with a XY-plotter, following graphs can be output:
- retention curve and hydraulic conductivity at input parameter values
- Water content profile at the end
- Comparison of measured and optimized value (for inverse mode).

Download

Download Windows executable with example cases
Download Linux executable with example cases
Source code

This software is written in FreePascal with an integrated development environment named Lazarus. You can freely download, modify, compile, and use it under following license (GPL ver.2).

License

This software is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This code is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. A copy of the GNU General Public License is available on the World Wide Web at http://www.gnu.org/copyleft/gpl.html.
New feature will be added on request if its implementation is easy. If you find a bug , please report it to the author.