A new tool to monitor drought conditions across New Zealand was launched today by the National Institute of Water and Atmospheric Research . Called The New Zealand Drought Index, it is being promoted as an easy-to-use, colour-coded map that defines the scientifically observed drought status of every New Zealand district.
The index is modelled on similar indexes used around the world, displaying the dryness of each district in five categories: dry, very dry, extremely dry, drought and severe drought. Each category is colour-coded from yellow for dry through to dark red for severe drought.
NIWA has developed the index in conjunction with the Ministry for Primary Industries over the past two years.
The ministry will use the new index as one of the criteria, alongside the wider impact on the rural community, to determine whether a drought is a medium- or large- scale adverse event. The Minister for Primary Industries then decides what support and recovery measures should be made available.
The index is based on four commonly-used climatological drought indicators: the Standardised Precipitation Index, the Soil Moisture Deficit, the Soil Moisture Deficit Anomaly and the Potential Evapotranspiration Deficit.
The index is presented as a map and as charts, enabling people to select districts and climatological indicators to keep track of particular areas.
It is expected to be a useful tool for farmers, irrigators, regional councils, water managers and anyone who needs to know about dry conditions. It is searchable by date and any combination of the drought indicators.
The NZDI can be accessed HERE.