Tuesday, 16 January 2007: 4:15 PM
Possible Impacts of Climate Change on Heavy Rainfall-related Streamflow: An Application to Thames River, London, Ontario, Canada
214B (Henry B. Gonzalez Convention Center)
The overarching purpose of this study was to estimate changes in occurrence frequency of future high-level streamflow events under climate scenarios for the Thames River, London, Ontario. Meteorological data used in the analysis included hourly/daily observations from London International Airport and climate stations located in the Thames River basin for the warm months (April–November) of 1958–2002. Six-hourly NCEP-NCAR upper-air reanalysis weather data at eight atmospheric levels for the same period were also used in the study. An autoregressive error model was applied to estimate future daily streamflow volumes, using downscaled GCM scenarios. Automated synoptic weather typing integrated with logistic and non-linear regression analyses was applied to estimate future daily rainfall amounts. Statistical downscaling methods were used to downscale GCM scenarios for three Canadian GCMs (CGCM1 IPCC IS92a, CGCM2 IPCC SRES A2/B2), one U.S. GCM (GFDL-CM2.0 IPCC SRES A2), and one German GCM (ECHAM5/MPI-OM IPCC SRES A2), for three-time windows (2016–35, 2046–65, 2081–2100). The historical runs (1961–2000) of the five GCMs were also downscaled and used for correction of the GCM model bias. Preliminary results show that under climate change, frequency of the future heavy rainfall and high flow events could increase in the middle and later part of this century.