Municipal water management in Canada is heavily dependent on the use of Intensity-Duration-Frequency (IDF) curves for planning, design, and operation of municipal water infrastructure. Many watershed management activities also rely on the use of IDF curves, including those related to water supply, water quality management and flood control. This web-based tool provides an approach for updating IDF curves under a changing climate and is available to anyone interested in developing IDF curves that incorporate projected climate change impacts.
While there is a need in almost every Canadian municipality to adapt to changing climatic conditions, there is a lack of necessary expertise within municipalities for implementing current research related to the impact of climatic change on IDF curves (Sandink et al, 2016). Thus, one of the primary aims of the tool is to standardize the IDF update process and make the results of current research on climate change impacts on IDF curves accessible to everyone (Simonovic et al., 2016; Sandink et al., 2016 and Schardong et al., 2020). The developers and supporting agencies believe that a freely available, computerized IDF update tool will aid in the selection of effective climate change adaptation options at the local level, advancing the decision-making capabilities of municipalities, watershed management authorities and other key stakeholders. The tool also provides a direct link between Canadian municipalities and the research community, creating opportunities for further research and innovation.
The IDF_CC tool is designed as a simple and generic decision support system to generate local IDF curve information that accounts for the possible impacts of climate change. It applies a user-friendly GIS interface and provides precipitation accumulation depths for a variety of return periods (2, 5, 10, 25, 50 and 100 years) and durations (5, 10, 15 and 30 minutes and 1, 2, 6, 12 and 24 hours), and allows users to generate IDF curve information based on historical data, as well as future climate conditions that can inform infrastructure decisions.
The IDF_CC tool stores data associated with 800 Environment and Climate Change Canada operated rain stations from across Canada. Roughly 500 of these stations have 10 years of data – the minimum time series used by Environment Canada to develop IDF curves for a specific location. Users can also create and share their own rain station information. Version 4.5 of the tool uses version 3.10 of the Environment Canada IDF dataset, released on Mar/2020 (Environment and Climate Change Canada, 2020). This dataset is available through the Gauged locations module accessible from the main menu of the tool.
The latest version of the IDF_CC tool also uncludes the module for Ungauged locations. The ungauged IDF curve estimates, for all durations (5, 10, 15, 30 min, 1, 2, 6, 12 and 24 hrs) and return periods (2, 5, 10, 25, 50 and 100 years), are extracted directly from the gridded dataset produced for the IDF_CC tool and described in detail in Gaur et al., (2020) and in the Technical and User's Manuals.
The IDF_CC tool allows users to select multiple future greenhouse gas concentration scenarios (RCPs) and apply results from a selection 24 Global Circulation Models (GCMs) and 9 downscaled GCMs that simulate various climate conditions to local rainfall data. To access functionalities and explore advanced options (for example, provide your own data/stations and carry out analysis for future scenarios using Global Circulations Models), please create your account or login if you have an account already.
The authors would like to acknowledge financial support by the Canadian Water Network Project under the Evolving Opportunities for Knowledge Application Grant to the third author for the initial phase of the project, and the Institute for Catastrophic Loss Reduction for continuous support of this project.
Slobodan P. Simonovic, Professor Emeritus, Western University
Andre Schardong, Western University
Abhishek Gaur, Western University
Dan Sandink, Institute for Catastrophic Loss Reduction