This repository contains the hydrological modeling setup and metadata for the National Adaptation Strategy (NAS) Project initiative led by Environment and Climate Change Canada (ECCC). The project aims to support climate resilience and evidence-based adaptation by generating large-scale hydroclimate data and modeling future water availability across Canada and its Transboundary River Basins (CTRB).
It utilizes the Modélisation Environnementale Communautaire-Surface & Hydrology (MESH) hydrological model, a powerful framework which simulates key surface and cold-region processes at regional and continental scales. Key simulated processes within MESH include streamflow, soil moisture-runoff dynamics, evapotranspiration, and snow accumulation. Results form the foundation for assessing future climate change impacts on water resources in CTRB.
Project work is organized into a series of phases referred to as Laps, presented in Figure 1. Each Lap expands on work developed in its predecessors through grouped exploration of input datasets, implementation of features and processes, and comparison with developed benchmarks. The iterative framework ensures continual improvement while controlling critical variables, ensuring integrity, reliability, and completeness.
Lap 0 starts with detailed documentation of a range of input geospatial and atmospheric forcing inputs, which are reused in future laps to minimize the extent of large-scale data processing. Details for each Lap are provided within each subdirectory, and summarized in Configuration_Sequence.csv
The timeline shown is indicative and not to scale and reflects expected technical dependencies between laps rather than fixed calendar commitments. Progression between laps is contingent on findings from preceding phases, including data quality, model behavior, and uncertainty characterization. As such, the lap design, scope, and timeline may be adjusted as the project progresses to accommodate emerging insights, evolving priorities, or newly identified technical requirements. This adaptive structure is intentional and supports transparency, scientific rigor, and reproducibility throughout the project development.
Figure 1: NAS hydrological modelling lap-based project design and indicative timeline
The objective of the NAS hydrological modelling project is to produce credible, regional-scale projections of future water availability across Canada under multiple climate scenarios. Key components include:
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Continental-scale MESH simulations across all Canadian and transboundary river basins
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Historical forcing using CaSR v2.1 and CaSR v3.1/3.2 datasets
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Climate-change simulations using CMIP5 and CMIP6 global climate models (e.g., CanESM5)
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Evaluation of streamflow, evapotranspiration, snow processes, soil moisture, and runoff
These outputs support federal, provincial, and cross-border water-management planning.
It is important that the conducted research is transparent, physically consistent, and reproducible. Therefore, the repository includes detailed model configurations, metadata, and preliminary outputs from historical and climate-change simulations using the MESH hydrological model.
A modified approach to the Model Agnostic Framework (MAF) developed by Kasra Keshavarz is applied, which organizes preprocessing and configuration steps into a repeatable workflow. By decoupling preprocessing from model-specific requirements, the procedure enables scalable and systematic incorporation of dataset updates through a High-Performance Computing (HPC) environment. Details on the MAF are provided in Lap 0.
The study domain encompasses all of CTRB, including basins which span the Canada–United States border.
Key transboundary systems include:
- Columbia River Basin
- Yukon River Basin
- Mackenzie-Peace-Liard Basin
- St. Mary-Milk River Basin
- Red-Assiniboine River Basin
- Great Lakes-St. Lawrence Basin
The domain reflects the geographical and hydrological diversity of Canada's river systems, emphasizing those of binational importance. A map of the river basins is provided in Figure 2.
Figure 2: Canada's River Basins and Transboundary Systems with MERIT-Hydro Geofabric (before and after Aggregation)
- Zelalem Tesemma, Environment and Climate Change Canada (zelalem.tesemma@ec.gc.ca)
- Sujata Budhathoki, Environment and Climate Change Canada (sujata.budhathoki@ec.gc.ca)
- Riley Damen, Environment and Climate Change Canada (riley.damen@ec.gc.ca)
- Frank Seglenieks, Environment and Climate Change Canada (frank.seglenieks@ec.gc.ca)
- Bruce Davison, Environment and Climate Change Canada (bruce.davison@ec.gc.ca)
This is an active research repository. Model configurations, parameters, and outputs are subject to change as improvements are made. Please contact the project team before using this material for publications or decision-making applications.