A new publication is now available.
Very recently, as part of the regular IDF_CC tool update, we investigated potential use of regional climate models (RCMs) for updating IDF relationships. In this, we analyzed the difference in updated IDF (Intensity-Duration-Frequency) relationships developed using global climate models (GCMs) and RCMs. The analyses are conducted using 369 selected Environment and Climate Change Canada hydro-meteorological stations from the IDF_CC tool database with record length longer than 20 years. A number of comparison experiments and two evaluation criteria were implemented. The RCMs generated lower extreme precipitation projections than the GCMs for the stations located in the Canadian prairies (provinces of Alberta, Saskatchewan, Manitoba). Stations located at the East and West coasts of Canada show a smaller difference in the projected extremes obtained using GCMs and RCMs. The use of RCMs shows increase in uncertainty when compared to GCMs. This result indicates that even when using regional climate models, it’s advisable to extend the analyses and include as many as possible models from different climate centers.
We are strongly encouraging users of the tool to read the publication "Application of Regional Climate Models for Updating Intensity-duration-frequency Curves under Climate Change" that documents the comparison. The paper is available from:
The Version 3.5 (May, 2019) of the IDF_CC tool, include:
- Updated dataset of IDF curves from the Environment and Climate Change Canada (ECCC) with precipitation data up to 2017
- New stations introduced by ECCC
- Changes in the names and/or code of stations introduced by ECCC
The ECCC IDF dataset implemented in this version of the IDF_CC tool can be obtained from ECCC (version 3.00, dated Feb 27, 2019): http://climate.weather.gc.ca/prods_servs/engineering_e.html.
The Version 3.0 (December, 2018) of the IDF_CC tool was updated with many new features (see Version 3 Technical Manual for details). Main features of the updated version include:
- IDFs for ungauged locations: Version 3 of the tool introduces a new dataset of IDF curves for ungauged locations in Canada. With the new module, users can obtain IDF curves for any location in the country, including regions where no station observations are available.
- A new user interface: A user-friendly and efficient interface provides for easy tool use.
- Bias corrected climate models: Bias corrected models developed by the Pacific Climate Impacts Consortium (PCIC) for Environment Canada (PCIC, 2013) have been added to the tool's climate model base, in addition to the Global Circulation Models (GCMs) used with Version 1. 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 bias corrected climate models were added to the Tool. The data is available for three Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5) (Meinshausen et al., 2011). The downscaled 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 3 of the tool uses GEV as the primary distribution to fit and update IDF data. The Gumbel distribution used by Environment and Climate Change Canada for fitting 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.