Climate change in southern Québec : drinking water supply and public health: climate projections for precipitation and runoff in southern Québec
One of the projected consequences of climate change (CC) is an increase in weather events or situations which until now have been rare, such as heavy precipitation or extended periods of drought. In this context, major infrastructure is likely to be affected by changes in the water regime, including the drinking water supply. Climatic variables that may affect volumes available for drinking water in a context of CC include rainfall and temperature. In the event of a significant change in rainfall resulting in a climate that is drier or more conducive to periods of drought, for example, drinking water production and distribution systems will be subject to unusual or exceptional constraints which they were not designed to handle. In addition, increased rainfall could affect the quality of raw water in the sites from which it is taken, raising the possibility of outbreaks of waterborne diseases.
These considerations show the importance of establishing and analyzing the current climate projections for southern Québec, if only on a preliminary basis, to see whether further analysis of the possible impact on drinking water supply systems should be carried out. In this context, a series of climatic projections of variables that are likely to affect the volume and quality of available water was produced. Two variables were seen as climatic indicators of trends in water availability: monthly precipitation and monthly runoff over the surface of the soil.