WaSim - A Computer-based training package
WaSim is a computer-based training package for the teaching and demonstration of issues involved in irrigation, drainage and salinity management. WaSim is easy to use, has minimal data requirements, good visualisation of model calculations, a reasonable level of accuracy and is flexible in terms of the range of water management situations that can be simulated.
Background
Computer simulation models are increasingly being used as teaching tools, as a replacement for, or adjunct to, traditional field or laboratory exercises. There are many water balance simulation models commonly used world-wide, which benefit from many years of development and validation. A majority of the existing models were developed for research use and are therefore unsuitable for educational use, or can only be used once extensive training in the use of the software has been completed.

The software package
Developed by HR Wallingford and Cranfield University, WaSim is a daily water balance model that simulates soil water / salinity relationships in response to different management strategies.

Designed for educational use, attention has been given to the ease of use of the interface, simple parameterisation and clear visualisation of results, rather than to the ultimate accuracy of the prediction, although this remains reasonable.

WaSim is available free of charge on the internet or on CD Rom. The package contains:

  • WaSim simulation software
  • WaSimET software for calculation of evapotranspiration
  • Drainage design modules for design of spacing and pipe diameter
  • Default crop and soil database
  • On-line help files
  • User, technical and tutorial manuals

What it covers
Visualisation of the simulation - To allow students to understand what is happening during simulations, the software uses a dynamic animation of the soil water and salinity in each of the modelled layers. The simulation can be paused and played using the 'playcontrols' to allow the tutor or student to stop it at a particular point.

  Presentation of results - WaSim simulates the soil water salinity relationships in response to different management strategies (e.g. drainage designs and water management practices) and environmental scenarios (e.g. weather data, soil types, cropping patterns). Wasim then enables quick graphical or tabulated comparisons, between these different scenarios.

User levels -To increase its scope as a teaching and learning aid WaSim enables users to choose from various levels of access. This allows tutors to create and protect databases and scenarios which can then be accessed and used by students.

The software provides the following capabilities:

  • WaSim simulates drainage to sub-surface tile (pipe) drains
  • WaSim runs on a daily time-step using actual rainfall and reference evapotranspiration data (an associated WaSim-ET program is provided to calculate reference evapotranspiration from weather station data) Simulations of up to 30 years in duration can be undertaken
  • Up to 3 crops (+ fallow) can be specified in rotation
  • Soil characteristics for a single layered soil can be specified.
  • WaSim can also be run as an unsaturated water balance simulation model, with irrigation, drainage/water table and salinity options switched off

Contributors
HR Wallingford Ltd; Cranfield University, Silsoe, Bedford, UK; IWASRI, Lahore, Pakistan.

Intended users
WaSim has been developed primarily for use as a teaching and learning aid for students and professionals wishing to learn about irrigation, drainage and salinity management.

Click here to install the software

Available at: http://www.dfid-kar-water.net/w5outputs.html and http://www.silsoe.cranfield.ac.uk/iwe/wasim/
For a CD version of the software, including manuals, contact:
International Development Group, HR Wallingford Ltd, Howbery Park, Oxon, OX10 8BA, UK
Tel: +44 (0) 1491 835381, Fax: +44 (0) 1491 826352, E-mail: w5outputs@hrwallingford.co.uk