CR 33:229-242 (2007)  -  doi:10.3354/cr033229

ABSTRACT: Over the west-central Canadian Prairies, precipitation was well below normal for a remarkable 8 consecutive seasons from September 2000 through August 2002. The precipitation deficits were associated with severe agricultural, hydrologic, and socio-economic impacts over much of the area. This study compares the spatial extent and severity of the 2001/2002 Canadian Prairie drought to previous droughts during the period of instrumental records. The Standardized Precipitation Index (SPI) and Palmer Drought Severity Index (PDSI) show that the worst and most prolonged Prairie-wide droughts during the period 1915–2002 occurred in the early part of the 20th century. Over the agricultural region of the Prairies, 2001 and 2002 generally ranked high in terms of spatial extent and severity of drought; at some stations the 2001/2002 drought was the most severe one on record. More importantly, it followed a prolonged lack of dry years, and this likely contributed to the severity of its impacts. Results from this study are an initial step toward the quantification and better understanding of both past and future drought occurrence over interior regions of North America.

KEY WORDS: Drought · Canadian Prairies · Standardized Precipitation Index · SPI · Palmer Drought Severity Index · PDSI · Climate change