History of Drought in Western Canada

How do scientists know that droughts occurred centuries before humans started measuring and recording data such as streamflow and precipitation?   Although we only have data from river gauges on river flows from the late 1800s and early 1900s, researchers have pushed our understanding of past river flows in the Prairies back to the early 1100s using tree-ring data[1].

Tree ring study and analysis (called dendrochronology) has been used to chart the occurrence of drought (and floods) in centuries before human measurements were taken and recorded. Although tree ring analysis is a complex undertaking, in the simplest terms, narrow rings indicate dry years, and wider rings indicate wetter years.

Climate change is expected to increase the risk of droughts (and floods) events in the coming decades.   In the blunt words of the Prairie Provinces Regional Perspectives Report [2], “With climate change, the Prairie provinces are projected to be much less cold than at present, with increased total precipitation, although mostly in winter and spring (Zhang et al., 2019). Evaporation and transpiration will also increase with warmer temperatures, leading to more frequent and intense droughts and soil moisture deficits over the southern Prairies during summer (Cohen et al., 2019).” (p. 11).

The effects of these droughts will vary according to the type of drought.   For example, a “meteorological drought”, caused by a lack of rain, is likely to immediately challenge dryland famers.   On the other hand, a “hydrological drought”, caused by low water levels as in Alberta in 2023 , is likely to present broader risks to irrigation, industrial and municipal supplies ([3], p.22).

Most of the information available on drought in the Prairies and its human impact focuses on the time period from the 1700s to present day.   We invite readers with a background in pre-settlement history to contact us with information on drought experienced in the region and its impacts on Aboriginal communities so that we can fill this gap. For more specific information on recent droughts in Alberta, we suggest that you use the links on this page to look at our pages on the 19^th Century, 20^th Century and 21^st Century droughts.   Given the current concern over water supply in western Canada at the moment, we will be updating our content more frequently to stay abreast of the situation as it unfolds during 2024.