The impact of recent climate on fire danger levels in New Zealand

Authors: Murray Dudfield, H. Grant Pearce, Geoff Cameron
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 2020, Issue N.Z.J.For. 65(4) 2021, pp 12-18, Jan 2021
Publisher: New Zealand Institute of Forestry

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Abstract: Have changes in weather conditions impacted on the day-to-day management of fires in the New Zealand forest and rural landscape? The aim of this paper is to look at the impacts of climate over the past four to five decades and to use an assessment of past and present fire danger levels in New Zealand to assess what changes, if any, have occurred. The objective is to evaluate the question as to whether a change in the availability of fuel for combustion has taken place between the periods pre-2000 and 2000 to 2020. This study looked to analyse three key components of the daily outputs from the NZ Fire Danger Rating System (NZFDRS) for 15 representative fire weather stations located throughout New Zealand. These historical datasets range in length from 24 to 59 years. The results from this largely qualitative analysis show a trend that fuel availability for combustion prior to the year 2000 generally does not appear to have increased in the past 20 years. A general overall decrease in regional fire danger levels was seen for South Island stations, apart from a minimal increase for Queenstown. For the North Island, regional fire danger levels indicated no overall change, but a nominal increase for the Central North Island, Auckland, Whanganui and Northland. Despite these differences between regions and islands, this study shows that outputs from the NZFDRS indicate a marginal overall downward trend in fire danger levels across New Zealand for the past 20 years compared to the period prior to 2000.

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