Seasonal and spatial patterns of rainfall trends on the Canadian prairie
We used regression analysis to establish linear trends of annual and seasonal rainfall amounts and number of events at 140 stations with 40 years of record from 1956 to 1995 across the Canadian Prairie. There has been a significant increase in the rainfall amounts and number of events. Increase in annual rainfall was 51 mm or about 16% of the 40 yr mean while the number of rainfall events increased by 17 or about 29%. Spring (January to April) experienced proportionately the largest increase, with amount and number increasing by 46% and 64%, respectively. This may be related to the conversion of snow to rain as a result of climatic warming during this period. The increase in rainfall amount and number of events during summer (May to August) were similar to the annual patterns. There was no significant increase in rainfall amount and number of events during the fall season (September to December). The increases in rainfall amount and number of events were not uniform across the prairies, with the least increase in rainfall amount and number of events in southern Manitoba, and the largest increase in Alberta and Saskatchewan. Little or no change in amounts occurred in the northern portion of the prairie provinces. The results confirmed that the prairies are not getting drier, however, there are seasonal and spatial differences in rainfall trends.
number of events
The following license files are associated with this item: