A report recently published in the Journal of Hydrology says droughts in the coming decades could be worse than at any time in the last three to four centuries.Co-author and PhD graduate Bethany Coulthard compared 350 years of tree-ring data and long-term drought records.She found at least 16 historical droughts worse than benchmarks used today by hydrologists and water managers in coastal regions.
The findings could have considerable impact on drought predictions for the area. Coulthard is set to meet next month with drought planners in the province to discuss drought predictions and modelling. “We have underestimated both how common and how severe the worst droughts are in this part of B.C.,” Coulthard says.
“If we don’t implement more conservative mitigation strategies, the region will be seriously underprepared when one of these droughts hits. The impacts would be disastrous for stream ecology and salmon.”
Unlike streamflow records, tree-ring records rarely miss the most extreme droughts, making tree rings better at providing a longer, more accurate snapshot of drought effects, researchers say in the report, also available on ScienceDirect.com.