March 12, 2025: NHS Webinar 4: Enhancing Hydrologic Data and Extreme Precipitation Analysis

The Canadian Water Resources Association (CWRA) is pleased to announce a webinar series in early 2025 in collaboration with Environment and Climate Change Canada’s National Hydrological Service (NHS). This series will highlight groundbreaking hydrology and hydraulics research conducted as part of the Flood Hazard Identification and Mapping Program (FHIMP) and showcase the latest advances in flood mapping science across Canada.

The webinars are targeted at flood mapping practitioners, researchers, interested parties, and the general public, offering an opportunity to tune in for presentations from subject matter experts at no cost to the participants. All webinars and accompanying materials will be offered in both official languages.

• James Craig (Professor and Canada Research Chair in Hydrologic Modelling and Analysis, University of Waterloo), “The Canadian Lake and River Hydrofabric (CLRH)”
  • Speaker Bio: Prof. Craig is a professor of civil & environmental engineering at the University of Waterloo and holds a Canada Research Chair in hydrologic modelling and analysis. He is lead author of the Raven hydrological modelling framework, a software tool used for watershed simulation and operational forecasting across Canada. His research focuses on the development and application of improved modelling algorithms, strategies, methods, and datasets.
  • Presentation Description: This work aimed to develop a high-resolution and high-quality national scale hydrofabric: a geospatial dataset which describes the extent and connectivity of subwatersheds of water bodies throughout Canada. The dataset includes parameters of interest to hydrologic modellers, including drainage area geometry ant topology for millions of outlet locations and widely used lake and river characteristics. Lastly, it integrates thousands of points of interest, including provincial and water survey of Canada stream gauge locations.
• Jonathan Jalbert (Professor, Polytechnique Montréal), “Interpolation of Precipitation Extremes in Canada for IDF Curve Construction at Unmonitored Locations”
  • Speaker Bio: Professor Jonathan Jalbert is a faculty member in the Department of Mathematics and Industrial Engineering at Polytechnique Montréal. His specialty lies in extreme value theory applied to environmental problems, particularly in the spatio-temporal modelling of extreme precipitation.
  • Presentation Description: Intensity-Duration-Frequency (IDF) curves describe the relationship between rainfall intensity, duration, and return period at a given location. They are crucial for infrastructure design, flood risk assessment, and stormwater management but are typically available only at specific measurement sites. A previous approach was developed to interpolate IDF curves by incorporating past climatology into a hierarchical Bayesian model using a Gaussian Markov random field. While this method improved accuracy and computational efficiency, its application was limited to Eastern Canada. This talk presents the integration of the Canadian Surface Reanalysis (CaSR) for interpolating extreme precipitation characteristics across Canada. The use of this reanalysis has been shown to enhance predictive performance, enabling more accurate IDF curve interpolation across Canada. By refining IDF curve estimation, this research supports improved planning, infrastructure resilience, and more effective water management strategies.
• Bryan Tolson (Professor, Civil and Environmental Engineering, University of Waterloo), “Enhancing LSTM-based Streamflow Prediction with a Spatially Distributed Approach”
  • Speaker Bio: Dr. Bryan Tolson is an expert in calibration and optimization of hydrologic and water resources models and has been a Professor at the University of Waterloo since 2005. Developer of the Dynamically Dimensioned Search optimization algorithm used around the world and by NOAA for operational calibration of the US National Water Model. Co-developer of BasinMaker lake and river routing network delineation software which is used by his research team to generate large-scale model agnostic lake and river routing products such as the Canadian Lake and River Hydrofabric and the Ontario Lake and River Routing Product.  Key collaborator on the Raven Hydrologic Modelling Framework software and CaSPAr archive of ECCC’s numerical weather forecasts.  Additional expertise in hydrologic machine learning applications.
  • Presentation Description:In this study, we propose a hybrid approach, namely the Spatially Recursive (SR) model, that integrates a lumped long short-term memory (LSTM) network seamlessly with a physics-based hydrological routing simulation for enhanced streamflow prediction. The lumped LSTM was trained on the basin-averaged meteorological and hydrological variables derived from 141 gauged basins located in the Great Lakes region of North America. The SR model involves applying the trained LSTM at the sub-basin scale for local streamflow predictions which are then translated to the basin outlet by an uncalibrated hydrologic routing model.

Available in French

About the Flood Hazard Identification and Mapping Program (FHIMP)

The Flood Hazard Identification and Mapping Program (FHIMP) is a collaborative, Government of Canada initiative led by Natural Resources Canada (NRCan), in partnership with Public Safety Canada, and Environment and Climate Change Canada (ECCC). The FHIMP is investing in updating Canada’s existing flood mapping capabilities.

In partnership with provincial and territorial governments, the FHIMP aims to complete flood hazard maps of higher-risk areas in Canada and make this flood hazard information accessible. These maps will help emergency planning by guiding the placement of evacuation routes and support land use planning by identifying locations for building critical infrastructure and flood mitigation structures like dikes. Flood maps provide reliable information on flood hazards and support decision-makers and Canadians in their efforts to adapt to a changing climate while protecting properties and lives.

A second component of the FHIMP is the funding of universities and non-profit organizations to develop flood science and integrate the impacts of climate change and uncertainty into flood hazard mapping. From 2021 to 2024, the Government of Canada invested $3M in this aspect of FHIMP and these webinars highlight research supported by this investment.

About CWRA

The Canadian Water Resources Association (CWRA) is a national registered charity comprised of members from the public, private and academic sectors who are committed to promoting responsible, innovative, and effective water resources management.

Formed in 1947 as the Western Canada Reclamation Association, CWRA is the only national organization addressing all water resources issues across all regions of Canada. We offer a range of services and programs focused on professional development, providing expertise and advice, education, and collaboration.