ICalc
ICalc is a computer program whose development was initiated by the Queensland Dairyfarmers' Organisation as part of the South East Queensland Irrigation Futures project, a joint project with the Department of Environment and Resource Management. The software was written by Queensland Primary Industries and Fisheries, Department of Employment, Economic Development and Innovation.
What does ICalc do?
ICalc is a relatively simple numerical model developed to enable estimates of irrigation requirements for a range of crops to be made across a number of locations in Queensland. The program uses daily rainfall and FAO56 evapotranspiration data, crop factors and irrigation method efficiency in its calculations. Daily rainfall and FAO56 evapotranspiration data is available in climate files downloaded from the Long Paddock - SILO web site, http://www.longpaddock.qld.gov.au/. This data has been summarised and included in a database which forms part of the program.
FAO56 evapotranspiration is an estimate of total water requirements to grow what is termed a "reference" crop. FAO56 requirements change with locality; hot dry climates have high FAO56 values and cool humid climates lower values.
Effective rainfall is rainfall that is not too light that it does not reach the root zone, nor too heavy that it runs through or off the soil. In this calculator rainfall less than 5 mm per day is ineffective as is rainfall above 50 mm per day.
Irrigation efficiency is a measure of how effective the irrigation plant is at applying the water requirements of the crop/pasture. It allows for losses in delivery and application of water from the water source; an efficiency of 1.00 is perfect.
In this calculator the daily FAO56 and effective rainfall are totalled for each month starting in 1970. If effective rainfall is taken away from the FAO56 requirements for a locality then you have an estimate of irrigation requirements of the reference crop for a particular locality:-
Gross crop irrigation requirement = Net crop irrigation requirement / Irrigation efficiency
The resulting calculation using FAO56, effective rainfall, crop factors and irrigation efficiency is:-
FAO56 evapotranspiration × Crop factor – Effective rainfall
Gross crop irrigation requirement = --------------------------------------------------------------------------
Irrigation efficiency
The program includes detailed notes showing the various screen layouts to allow you to get the most out of the program.
How do I get a copy?
Due to the size of this program, a CD copy is available on request. For a copy of the CD please contact:
Gordon Simpson
Dairy Systems Modeller
Department of Employment, Economic Development and Innovation
Email gordon.simpson@deedi.qld.gov.au
Or if you have a broadband internet connection you could download the install files right now!
Instructions to Download - This file is about 2 MB. ICInstall.zip is a new installation
1. Right click on the ICalc icon and use the "Save Target As" option to download the file to your computer.
2. When saved to your computer unzip the file, a new subdirectory will be created "ICInstall".
3. Run the file "ICInstall.exe" in this subdirectory and follow the prompts.
For technical enquiries please contact: Mark Callow
Dairy Research Scientist - Agronomy
Department of Employment, Economic Development and Innovation
Email mark.callow@deedi.qld.gov.au