OpenFEWS

OpenFEWS is an open and shareable configuration for an operational hydrological forecasting system with Delft-FEWS. This repository is meant to share developments and receive input from the forecasting community. It is experimental and demonstration only.

The workflows allow data access and processing for a number of public data sources in Canada and the US. Primary data sources are the NOAA Operational Model Archive and Distribution System (NOMADS) and the Meteorological Service of Canada Open Data, but also include a variety of snow and meterological re-analysis products, such as ERA5.

This repo is intended for those with some experience with the Delft-FEWS software. It is hosted on GitHub so that users can access workflows, model connections and displays for their own use. Please feel free to use the configuration to develop and improve your own applications. Also make contributions back! New data, methods, models and displays are all welcome.

Hydrological Models

OpenFEWS currently contains several hydrological modelling frameworks over the Yukon River Basin, a transboundary basin across the Yukon and Alaska and the Bow River Basin in Alberta.

SUMMA

SUMMA or the Structure for Unifying Multiple Modeling Alternatives is a hydrologic modeling approach that is built on a common set of conservation equations and a common numerical solver, which together constitute the structural core of the model.

SUMMA can be used to configure a wide range of hydrological model alternatives. Different modeling approaches can then be implemented within the structural core, enabling a controlled and systematic analysis of alternative modeling options, and providing insight for future model development. SUMMA allows different model representations of physical processes and spatial configurations to be flexibly implemented and tested. Creation of SUMMA models is enabled by the well documented CWARHM workflow. This provides all tools necessary to build SUMMA models from scratch.

Raven

Raven is flexible hydrological modelling framework, allowing flexibility in spatial discretization, interpolation, process representation, and forcing function generation. In this repository, a semi-distributed HBV-EC concept model is implemented to demonstrate the model bindings and connections.

MESH

MESH (short for Modlisation Environnementale communautaire Surface and Hydrology) is a Canadian community land-surfacehydrology modeling system developed primarily by Environment and Climate Change Canada (ECCC). It is designed to simulate both the energy and water budgets over watersheds, regions, or the entire country, and is often used for river forecasting, climate change impact studies, and water resources planning.

wflow

wflow allows multiple distributed model concepts are available, allowing the use of open earth observation data, making it the hydrological model of choice for data scarce environments. Based on gridded topography, soil, land use and climate data, wflow calculates all hydrological fluxes at any given grid cell in the model at a given time step. Creation of wflow models is enabled by the HydroMT python package. In CanOpenFEWS, a wflow_sbm model is included for the Bow River. The parameterization of this model is automatically derived using HydroMT, by making use of transfer functions that relate open geographic data (soil, land use, land cover, etc.) to a parameter value. The model can be further improved by calibrating its most sensitive parameters.

Getting Started

If you are truly new to this software, it may be better to begin with the information available on the Delft-FEWS website. At this link, you can find the latest information, instructions and community developments. Configuring Delft-FEWS comes with a steep learning curve, but once you are familiar with it, this repository can help to minimize reinventing the wheel by sharing configuration and it is a great way to test and share new developments (models, code, etc.).

Installation of Delft-FEWS

Download and installation instructions are available at this webpage, at the bottom. Delft-FEWS is free to use, but please note that a end-user license agreement is required. For further detail on obtaining Delft-FEWS, including new releases, please contact fews-pm email. The newest Delft-FEWS versions are only available through fews-pm email, but older versions can be directly downloaded from the website. This configuration has been tested with the v2023.01 of Delft-FEWS. It is possible that some functionalities do not work with other (older) versions of Delft-FEWS.

Please note that Delft-FEWS runs on Windows and Linux, and is not normally run on Mac OS.

Using the OpenFEWS configuration

A complete functioning configuration is available on this GitHub repository.

If you do not plan on contributing back to the repository, it can simply be downloaded from the main page. If you do plan on contributing, which is very welcome, you will need to use git, or a program like GitHub Desktop.

License

OpenFEWS is licensed under an MIT license, which generally is quite open and permissive. Please see the LICENSE file for details.

How to contribute?

Contributions to OpenFEWS are much appreciated. However, to ensure continuity and a stable code base, we ask you to do the following when you plan to contribute with changes, new config or new models:

(1) Fork the repository

(2) Create a new branch

All contributions should be made in a new branch under your forked repository. Working on the master branch is reserved for Core Contributors only. Core Contributors are developers that actively work and maintain the repository. They are the only ones who accept pull requests and push commits directly to the pysteps repository.For more information on how to create and work with branches, see Branches in a Nutshell in the Git documentation.

(3) Create a pull request based on the changes in your branch

The pull requests are checked by the main contributors and merged with the main repository once accepted.

Citations

OpenFEWS

Casson, D., & Imhoff, R. (2025). CH-Earth/OpenFEWS: v1.0 release (Version 0.1) [Computer software]. Zenodo. https://doi.org/10.5281/zenodo.16884208

@software{casson_imhoff_2025_openfews,
  title     = {CH-Earth/OpenFEWS: v1.0 release},
  author    = {Casson, David R. and Imhoff, Ruben},
  year      = {2025},
  month     = aug,
  version   = {0.1},
  publisher = {Zenodo},
  doi       = {10.5281/zenodo.16884208},
  url       = {https://doi.org/10.5281/zenodo.16884208}
}

Delft-FEWS

Werner, M., Schellekens, J., Gijsbers, P., van Dijk, M., van den Akker, O., and Heynert, K. (2013). The Delft-FEWS flow forecasting system. Environ Modell Softw, 40, 6577. doi: 10.1016/j.envsoft.2012.07.010.

SUMMA

Clark, M. P., B. Nijssen, J. Lundquist, D. Kavetski, D. Rupp, R. Woods, E. Gutmann, A. Wood, L. Brekke, J. Arnold, D. Gochis, and R. Rasmussen, 2015a: A unified approach to process-based hydrologic modeling. Part 1: Modeling concept. Water Resources Research, 51, doi: 10.1002/2015WR017198

Clark, M. P., B. Nijssen, J. Lundquist, D. Kavetski, D. Rupp, R. Woods, E. Gutmann, A. Wood, D. Gochis, R. Rasmussen, D. Tarboton, V. Mahat, G. Flerchinger, and D. Marks, 2015b: A unified approach for process-based hydrologic modeling: Part 2. Model implementation and example applications. Water Resources Research, 51, doi: 10.1002/2015WR017200

Knoben, W. J. M., Clark, M. P., Bales, J., Bennett, A., Gharari, S., Marsh, C. B., et al. (2022). Community Workflows to Advance Reproducibility in Hydrologic Modeling: Separating model-agnostic and model-specific configuration steps in applications of large-domain hydrologic models. Water Resources Research, 58, e2021WR031753. doi: 10.1029/2021WR031753

Raven

Craig, J.R., G. Brown, R. Chlumsky, W. Jenkinson, G. Jost, K. Lee, J. Mai, M. Serrer, M. Shafii, N. Sgro, A. Snowdon, and B.A. Tolson, Flexible watershed simulation with the Raven hydrological modelling framework, Environmental Modelling and Software, 129, 104728, July 2020 doi:10.1016/j.envsoft.2020.104728

MESH

Pietroniro, A., V. Fortin, N. Kouwen, et al. Development of the MESH Modelling System for Hydrological Ensemble Forecasting of the Laurentian Great Lakes at the Regional Scale. Hydrology and Earth System Sciences 11, no. 4 (2007): 127994. doi:10.5194/hess-11-1279-2007

wflow

van Verseveld, W.J., Weerts, A.H., Visser, M., Buitink, J., Imhoff, R.O., Boisgontier, H., Bouaziz, L., Eilander, D., Hegnauer, M., ten Velden, C., and Russell, B. (2022). Wflow_sbm v0.6.1, a spatially distributed hydrologic model: from global data to local applications. Hydrol Earth Syst Sc Discussion. doi: 10.5194/gmd-2022-182.