By Stanley Mastrantonis
In Australia, rainfall percentiles were established as the de-facto measure for classifying meteorological drought and are used as triggers for drought support programs. Generally speaking, drought is defined based on an entire calendar year’s rainfall, and though this approach is useful when assessing meteorological or hydrological droughts, this period of rainfall may not be ideal for defining agricultural drought. For this work, I have demonstrated how drought frequency, extent and patterns change when drought is assessed across the growing season instead of an entire year. Additionally, I have suggested some novel analytical tools and approaches that can be used to assess drought and plant water stress at sub-paddock scales, which may be more appropriate for drought assessment in WA.
