Identifying common traits among Australian irrigators using cluster analysis.

In Australia there is a growing awareness that the over-allocation of water entitlements to irrigators needs to be reduced so that environmental flow allocations can be increased. This means that some water will need to be acquired from irrigators and returned to the environment. Most current water reform policies assume that irrigators are solely motivated by profit and will be willing sellers of water, but this might be an untenable approach. Authorities will need to consider new ways of encouraging the participation of irrigators in water reform. The main aim of this research was to identify the non-commercial influences acting on irrigators' behaviour, especially the influence of the values that they hold toward family, land, water, community and lifestyle. The study also aimed to investigate whether it is possible to group irrigators according to these values and then use the groupings to describe how these might affect their willingness to participate in environmental reforms. We clustered the irrigators into three groups with differing orientations; (i) Investors [25%]-profit oriented, (ii) Lifestylers [25%]-lifestyle oriented, (iii) Providers [50%]-family-succession oriented. This research indicates that when designing policy instruments to acquire water for environmental purposes policy-makers should pay more attention to the factors influencing irrigators' decision making, especially non-commercial factors.

Magnetic Field Stabilization for Magnetically Shielded Volumes by External Field Coils.

For highly sensitive magnetic measurements, e.g., a measurement of the neutron electric dipole moment (EDM), the magnetic field has to be stable in time on a level below picoTesla. One of several measures we employ to achieve this uses an external field coil system which can stabilize the ambient external field at a predefined value. Here we report on the construction and characterization of such a system in the magnetic test facility at PSI. The system actively stabilizes the field along the axis of the EDM experiment by means of four coils in a Helmholtz-like configuration. Additional coils serve to compensate for transverse ambient field components. Because of the long integration times in the EDM experiment (about 100 s or more) only slow disturbances have to be corrected for. The performance of the system has been measured using static and moving magnetic sources and suppression factors in excess of 200 have been observed.