Standardized precipitation index (SPI) data over Quebec and Abitibi-Témiscamingue

This study assesses historical and projected drought conditions across the Abitibi-Témiscamingue (AT) region of Quebec for the period 1991-2100 using the Standardized Precipitation Index (SPI) and precipitation data derived from CMIP6 climate models under three Shared Socioeconomic Pathways (SSP2-4.5, SSP3-7.0, and SSP5-8.5) culled from Ouranos for all the five regional country municipalities (RCMs) of AT. Results show that although total annual precipitation is projected to increase across all RCMs, this increase does not uniformly mitigate drought risk. The analysis reveals spatial disparities in both historical and projected drought severity, with northern municipalities—specifically Abitibi, West Abitibi, and Rouyn-Noranda—consistently experiencing more frequent and intense droughts compared to southern municipalities such as Vallée-de-l’Or and Témiscamingue. Under SSP2-4.5 and SSP3-7.0, SPI values indicate mildly to moderately dry conditions persisting in these northern regions up to 2100, with Rouyn-Noranda exhibiting the most negative SPI values (reaching -1.40). In contrast, Vallée-de-l’Or and Témiscamingue maintain positive SPI values, suggesting conditions ranging from near normal to moderately wet. Interestingly, SPI projections under the high-emission SSP5-8.5 scenario do not show additional drought intensification beyond those observed under SSP3-7.0, indicating a possible saturation in SPI response or the influence of regional water management adaptations. While increased precipitation under higher emissions may appear beneficial, the SPI’s exclusion of temperature-driven evapotranspiration could limit its ability to capture the full scope of drought risk. These findings highlight the persistence of mild to moderate drought conditions in northern AT, the normalization of water stress in vulnerable municipalities, and the urgent need to consider both climatic and socio-demographic factors in regional adaptation strategies. This research contributes to understanding of how climate change will shape hydroclimatic extremes in high-latitude continental regions of Canada.