Seasonal variability in production conditions is tracked through five phases based on percentile thresholds calculated from historic rainfall, soil moisture and plant growth information, as well as the trend in rainfall conditions.
Primary producers can use this information to prepare for changing conditions, and to make strategic and tactical decisions reflecting the current season.
The movement of seasonal conditions through the five phases is based on the following thresholds.
CDI Phase | Technical definition | Description - typical field conditions |
|---|---|---|
Intense Drought | All three indicators (rainfall, soil water, plant growth) are below the 5th percentile | Ground cover is very low, soil moisture stores are exhausted and rainfall has been minimal over the past 6-12 months. |
Drought | At least one indicator is below the 5th percentile | Conditions may be very dry, or agronomic production is tight (low soil moisture or plant growth). It is possible to be in Drought when there has been some modest growth, or a few falls of rain. |
Drought Affected (intensifying) | At least one indicator is below the 30th percentile and the rainfall trend is negative over the past 90 days. | Conditions are deteriorating; production is beginning to get tighter. Ground cover may be modest, but growth is moderate to low for the time of year. When indicators are close to the Drought threshold drought conditions are severe. |
Drought Affected (weakening) | At least one indicator is below the 30th percentile and the rainfall trend is positive over the past 90 days. | Production conditions are getting tighter, but there have been some falls of rain over the past month. It is rare to enter the Recovering phase from the Non-Drought category; Usually there is a quick (1-2 week) transition into Drought Affected or Drought. When indicators are close to the Drought threshold drought conditions are severe. |
Recovering | All indicators are below the 50th percentile but above the 30th percentile | Production is occurring but would be considered ‘below average’. Full production recovery may not have occurred if this area has experienced drought conditions over the past six months. |
Non-drought | At least one indicator is above the 50th percentile. | Production is not limited by climatic conditions. |
Do you need help with drought? Go to NSW DPI’s Drought Hub