What's new

Recent updates of the IDF_CC Tool

What's new

NEW VERSION: IDF_CC tool version 2.0 has been released (July, 2017):

The new Version 2.0 of the IDF_CC tool is now available for beta testing. The tool has been updated with many new features (see Version 2 Technical Manual for details). Main features of the updated version include:

  • A new user interface: A friendly and efficient user interface provides for easy communication with tool database and modelbase.

  • Bias corrected climate models: The Global Circulation Models (GCMs) used with Version 1 have been replaced with bias corrected models developed by the Pacific Climate Impacts Consortium (PCIC) for Environment Canada (PCIC, 2013). Statistically downscaled daily Canada-wide climate scenarios, at a gridded resolution of 300 arc-seconds (0.0833 degrees, or roughly 10 km) for the simulated period of 1950-2100 are used in this updated version of the tool. Daily precipitation from nine climate models bias corrected with two methods are used, resulting in 18 climate model datasets. The data is available for three Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5) (Meinshausen et al., 2011). The downscaling outputs are based on Global Climate Model (GCM) projections from the Coupled Model Intercomparison Project Phase 5 (CMIP5; Taylor et al., 2012) and historical daily gridded climate data for Canada (McKenney et al., 2011).

  • Generalized Extreme Value (GEV) distribution: Version 2 of the tool uses GEV as the primary distribution to fit and update IDF data. The Gumbel distribution used by Environment Canada for fitting the IDF data is outdated and is only kept within this version to provide users with the opportunity to compare official IDF curves obtained using historical data with those obtained by the IDF_CC tool. Many recent studies have shown that GEV distribution provides better fit to annual maximum precipitation (AMP) series than the Gumbel distribution (summarized in Millington et al., 2011). The L-moments method (Hosking, 1997) has been employed in the new version of the tool for GEV parameter estimation. The IDF updating procedure has also been modified to reflect the use of the GEV distribution (see the Version 2 Technical Manual for details).

  • Hosking, J.R.M., Wallis, J.R. (1997). “Regional Frequency Analysis”. Cambridge University Press, Cambridge
  • McKenney, D.W., M.F. Hutchinson, P. Papadopol, K. Lawrence, J. Pedlar, K. Campbell, E. Milewska, R. Hopkinson, D. Price, and T. Owen, (2011): Customized spatial climate models for North America. Bulletin of the American Meteorological Society, 92, 12, 1611-1622.
  • Meinshausen, M., S. J. Smith, K. Calvin, J. S. Daniel, M. L. T. Kainuma, J-F. Lamarque, K. Matsumoto, S. A. Montzka, S. C. B. Raper, K. Riahi, A. Thomson, G. J. M. Velders, D.P. P. van Vuuren (2011): The RCP greenhouse gas concentrations and their extensions from 1765 to 2300. Climatic Change, 109(1-2), 213-241.
  • Millington D., S. Das, and S.P. Simonovic (2011): The Comparison of GEV, Log-Pearson Type 3 and Gumbel Distributions in the Upper Thames River Watershed under Global Circulation Models, Millington, N., S. Das, and S.P. Simonovic (2011). Water Resources Research Report no. 077, Facility for Intelligent Decision Support, Department of Civil and Environmental Engineering, London, Ontario, Canada, 53 pages. ISBN: (print) 978-0-7714-2898-2; (online) 978-0-7714-2905-7. Available at: http://www.eng.uwo.ca/research/iclr/fids/publications/products/77.pdf , last accessed July 2017.
  • PCIC (2013): Data Portal. Available at https://pacificclimate.org/data , last accessed July 2017.
  • Taylor, K.E., R.J. Stouffer, and G.A. Meehl, (2012): An Overview of CMIP5 and the Experiment Design. Bulletin of the American Meteorological Society, 93, 485–498.

Research and Development Team

Slobodan P. Simonovic, Professor, Western University

Andre Schardong, Post Doctoral Fellow, Western University

Dan Sandink, Institute for Catastrophic Loss Reduction


Institute for Catastrophic Loss Reduction (www.iclr.org/)

IDF_CC Tool 2.0