A prototype DSS to evaluate irrigation management plans
Inefficient irrigation strategies delivering an excess of irrigation water can result in pesticides and nitrates being leached to groundwater. However, information on the environmental impact of irrigation strategies is not readily available to either growers or the local authority responsible for water consents. Improved irrigation practices can be promoted by making this information more readily available in the form of a decision support system (DSS) linked to the water allocation process. Under this approach, growers would be required to submit to the local authority an irrigation management plan (IMP) which details how they intend to irrigate the crop in each of their management blocks. Sufficient information about the soil, crop, irrigation system and scheduling mechanism would have to be supplied in the IMP to allow it to be evaluated from an environmental impact perspective. The IMP is evaluated by a water allocation consent officer with the help of the decision support system, in which is incorporated environmental impact knowledge. This DSS integrates a simulation model SWIM, a decision tree, and scientific soil hydraulic data. The simulation model is used to estimate the likely water requirement of the grower under the IMP. The decision tree represents expert heuristics on the effects of the various irrigation strategies. The soil hydraulic data provides soil hydraulic properties to SWIM and to the decision tree. Local authorities and growers can use the DSS to learn about the likely environmental impact and water requirements of each grower.
dss irrigation water allocation expert system