The flow of water into Canterbury rivers is likely to drop because of less ice in the Southern Alps, says climate scientist Jim Salinger.
His research shows the Southern Alps has 30 per cent less ice than 36 years ago and this would continue to decline. Water would be more likely to fall on the alps as rain, rather than snow, and run straight off, while the snow that did settle would melt and run off earlier.
It meant there would be less water flowing into rivers on the Canterbury Plains during summer, while more would come down in winter months.
Salinger said high temperatures were expected to continue this year and while average temperatures could drop for individual years, New Zealand and the world would get warmer.
Federated Farmers vice-president William Rolleston said it highlighted the need to look at ways of collecting and storing water during winter to use in drier months.
Rolleston said any research that could forecast future weather patterns was vital as it could help farmers predict what crops to plant.
Salinger said New Zealand had emerged from its second-warmest year and warmest winter on record.
Last year as a whole was the country's second-warmest on record with temperatures on average 0.84 degrees Celsius above normal.
The New Zealand regional mean temperature for 2013 was derived from 22 land stations, and three offshore islands.
Record annual mean temperatures were recorded in the southeast of the South Island, Salinger said. Masterton, Omarama, Timaru, Invercargill and the Chatham Islands all had record years.
Lincoln had its second warmest year, with an average temperature of 12.42C , 0.89C higher than its long-term average.
Winter 2013 mean temperatures were 1.27C above the 1961-1990 average, the highest on record.
Salinger said the above-average temperatures were expected to continue this year.
- The Press