Definitions for "Droughts"
or severe rainfall deficits, occur when a 12-month period receives less rain than in the driest 10% of calendar years. In eastern and northern Australia, they are often associated with strongly negative SOI values, commonly referred to as El NiƱo event or episode.
period of deficiency of moisture in the soil such that there is inadequate water required for plants, animals, and human beings.52,53,54