Source: NIWA – National Institute of Water and Atmospheric Research
A weekly update describing soil moisture patterns across the country to show where dry to extremely dry conditions are occurring or imminent. Regions experiencing significant soil moisture deficits are deemed “hotspots”. Persistent hotspot regions have the potential to develop into drought.
Recent rainfall and current soil moisture conditions:
North Island:
- Meagre rainfall was widespread across the entire North Island in the past week, with most locations receiving 5 mm or less. Isolated pockets up to 15 mm were observed in the Coromandel Peninsula and parts of the Central Plateau.
- This resulted in moderate soil moisture decreases across the entire North Island.
- The driest soils across the North Island, when compared to normal for this time of the year, are found in eastern Northland, while the wettest soils for this time of the year are found in western and southern Waikato.
- Hotspots are currently located across the Far North and eastern Northland, far northern Auckland, coastal Gisborne, southern Hawke’s Bay to Wairarapa, and parts of western Wellington.
- As of 13 March, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in Northland, Auckland, part of the Coromandel Peninsula, eastern Bay of Plenty, and much of the lower North Island. Very dry to extremely dry conditions are located in much of Northland and Wellington.
South Island:
- Much like the North Island, a majority of the South Island saw only meagre rainfall in the past week, with 5 mm or less observed in most of the upper and eastern South Island.
- Pockets of the upper West Coast, central Canterbury, and Southland received up to 20 mm.
- Weekly rainfall totals in the lower West Coast and Fiordland were much higher, however, with generally 50-100 mm observed.
- This resulted in small to moderate soil moisture decreases across most of the upper and eastern South Island, with little change observed elsewhere.
- The driest soils across the South Island, when compared to normal for this time of the year, are found across parts of Tasman, Nelson, Marlborough Sounds, and Canterbury, while the wettest soils for this time of the year are found in western Southland.
- Hotspots are currently located across much of the upper and eastern South Island, including eastern Tasman, Nelson, parts of Marlborough, nearly all of Canterbury, and eastern Otago.
- As of 13 March, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in eastern Tasman, Nelson, Marlborough, northern and southern Canterbury, and eastern Otago. Very dry to extremely dry conditions are located in Nelson, Marlborough, parts of northern and far southern Canterbury, and northern Otago.
Pictured above: Soil Moisture Anomaly Maps, relative to this time of year. The maps show soil moisture anomalies over the past two weeks.
As of 13 March, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in Northland, Auckland, part of the Coromandel Peninsula, eastern Bay of Plenty, much of the lower North Island, eastern Tasman, Nelson, Marlborough, northern and southern Canterbury, and eastern Otago. Very dry to extremely dry conditions are located in much of Northland, Wellington, Nelson, Marlborough, parts of northern and far southern Canterbury, and northern Otago. Please note: some hotspots in the text above may not correspond with the NZDI map. This difference exists because the NZDI uses additional dryness indices, including one which integrates the rainfall deficit over the past 60 days. Changes are therefore slower to appear in the NZDI compared to soil moisture anomaly maps that are instantaneously updated.
New Zealand Drought Index (NZDI) – 13 March 2024 [NIWA]
