River flows in New Zealand have changed dramatically over the past 50 to 90 years as the climate has varied, a new study has found.
River flows in New Zealand have changed dramatically over the past 50 to 90 years as the climate has varied, a new study has found.
Marked changes in average summer and winter river flows were identified in the study, carried out by researchers at Te Herenga Waka—Victoria University of Wellington and NIWA. Results of the research are published in the paper “Spatiotemporal Trends in Near-natural New Zealand River Flow” in the Journal of Hydrometeorology.
While parts of the North Island have seen extreme rainfall this summer, long-term trends show that, on average, summer river flows are decreasing in these areas and they’re likely to be getting drier.
“Typical summer river flows have significantly decreased for much of the North Island, with the exception of Manawatu and Wellington,” says lead author Laura Queen, a Ph.D. candidate at Victoria University of Wellington who is based at NIWA.
“In winter, average river flows have also decreased in the upper North Island but significantly increased on the West Coast of the South Island and in Fiordland and Southland,” she says.
