Characterizing the Surface Features of the 1999-2005 Canadian Prairie Drought in Relation to Previous Severe Twentieth Century Events

The Canadian Prairie drought of 1999-2005 negatively affected several activities including agriculture, stream flow, hydro-electric production and forest fires. However, surface drought conditions and associated impacts were neither spatially nor temporally uniform. Following an assessment of several gridded temperature and precipitation datasets, this study incorporates the Standardized Precipitation Index (SPI) and the Palmer Drought Severity Index (PDSI) to characterize the surface features of the 1999-2005 Prairie drought in terms of its origin, spatial propagation, persistence and termination. This includes the development and application of a newly proposed multi-stage concept to characterize and classify drought. These characteristics are then compared to previous major Prairie droughts in the instrumental record. Results show that the 1999-2005 drought originated in the Great Plains of the United States and expanded into southwestern Alberta in late 1999 to early 2000. It then intensified to cover much of south-central Alberta and Saskatchewan in 2001. By 2002, it mainly affected the northern agricultural regions of these two provinces. This was followed by a widespread end to drought conditions in 2004 to 2005. Comparisons with other major twentieth-century droughts on the Prairies revealed many similarities, but notable differences, with the 1999-2005 episode. Analyses also showed that these major Prairie droughts originated in a variety of regions, although several can be traced back to the northern United States. Results from this investigation aid in a better understanding of temporal and spatial features associated with major Canadian Prairie droughts and can be used to help improve preparation and adaptation mechanisms for future drought occurrences.