ClimateChange Assessment Guide.pdf - University of Waterloo

E-18Guide for Assessment of Hydrological Effects of Climate Change in OntarioHSP-F requires numerous meteorological inputs to perform water balance simulations. The snow accumulation andmelt routines employ complex algorithms that are dependent upon several meteorological parameters. Componentsof the snow accumulation and melt routines include determinations of conditions necessary for precipitation to fall assnow, latent heat and heat transfer within the various phases of the snowpack and the rates of phase change in thesnowpack (Bicknell et al., 2001). To meet all of the climate data input needs of HSP-F, the following parameters arerequired:• Precipitation rate (hourly);• Air temperature (hourly);• Wind speed (hourly);• Solar radiation (hourly);• Dew point temperature (daily); and• Potential evapotranspiration (hourly).Climate data was acquired from Environment Canada for stations in Orangeville (#6155790) and Lester B. PearsonInternational Airport (LBPIA) (#6158655).Figure 3-3 displays the total annual rain and snow for Orangeville and Figure 3-4 displays monthly average rain andsnow, for the period 2000 to 2007 (to end of July). This includes the model spin-up year (i.e., 2000) and thecalibration/validation period used in this study. Average recorded annual rainfall was 732 mm/y, which is close to the1971-2000 normal for Orangeville MOE of 740 mm/y. Total annual average snowfall of 183 mm/y was 14% above the1971-2000 normal of 160 mm/y. Thus, average annual total precipitation of 915 mm was about 2% above the 1971-2000 annual average.12001000RAINSNOW800mm.60040020002000 2001 2002 2003 2004 2005 2006 2007*(*Includes January through July 2007)Figure 3-3: Annual total rain and snow in Subwatershed 19, 2000 to 2007.