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Half a Millennium of Droughts on Canada's Vancouver Island

Paper Reviewed
Coulthard, B. and Smith, D.J. 2016. A 477-year dendro-hydrological assessment of drought severity for Tsable River, Vancouver Island, British Columbia, Canada. Hydrological Processes 30: 1676-1690.

To provide a long-term perspective on the nature of recent droughts occurring on Vancouver Island, in the words of Coulthard and Smith (2016), they developed "a 477-year-long dendro-hydrological reconstruction of summer stream flow for the island's Tsable River based on a network of annual tree-ring width data." And what did this effort reveal?

The two Canadian researchers report that since AD 1520, fully "21 droughts occurred that were more extreme than recent 'severe' events like those in 2003 and 2009." And in light of these findings, they conclude that "the fact that recent 'extreme' events fall within a natural range of multi-century variability means that rather than being considered anomalies, extreme droughts should be expected and incorporated into drought management strategies."

Put another way, there would appear to be nothing unusual, unnatural or unprecedented about Vancouver Island's most recent string of extreme drought events. And, therefore, there should be no compelling reason for anyone to become overly-concerned about a climatic phenomenon that has manifest itself multiple times over the past five centuries and that will probably continue to occur in like manner over the next five centuries.

Posted 7 November 2016