Watershed Modeling Workshop
Distributed Watershed Modeling for Flood Simulation: Bringing Research Tools to Practice
Workshop Description
Watershed modeling is a critical tool for engineers and scientists working in flood risk assessment, infrastructure design, and water resources planning. In Arizona, practitioners commonly rely on HEC-HMS for event-based hydrologic simulations following methodologies established by the Arizona Department of Transportation (ADOT) and the Flood Control District of Maricopa County (FCDMC). While effective, these semi-distributed approaches may not capture the full spatial variability of watershed processes that influence flood behavior.
This workshop introduces participants to a new generation of watershed modeling tools by comparing HEC-HMS with tRIBS (TIN-based Real-time Integrated Basin Simulator), a fully-distributed, open-source hydrologic model developed over 20+ years of research and now available on GitHub. Participants will work through a real-world case study in the South Mountain Fan (SMF) watershed in the Phoenix metropolitan area, applying the tRIBS model to the largest observed streamflow event on August 12, 2014, and two subsequent events within the same summer. Attendees will gain first-hand insight into the capabilities, limitations, and the value added to consulting and design projects by applying distributed hydrologic models.
A key feature of this workshop is the use of modern cyberinfrastructure. Participants will use GitHub Codespaces and Jupyter Notebooks to interact with tRIBS, eliminating the need for complex software installations and demonstrating how cloud-based tools are changing the landscape of hydrologic modeling. All workshop materials have been developed and tested in a university course at Arizona State University during the Spring 2026 semester.
Who should attend:
- Practicing hydrologists
- Civil and water resources engineers
- Floodplain managers
- Consultants
- Students interested in expanding their modeling toolkit beyond traditional approaches.
Instructor:
Enrique R. Vivoni, Ph.D., P.E. & Josh Cederstrom, M.S.
Time / Date:
September 9, 2026, 8:00 AM to 12 PM
Location:
City of Flagstaff Water Services, 2323 Walgreens Street, Suite 100 Flagstaff, AZ 86004
Free parking, park on south side of building and enter through double doors
Limit:
20 people (first-come, first-served)
Cost:
See below. Early Bird pricing ends August 12th
PDHs:
4
Course Requirements:
Participants must bring:
-
- Laptop (Windows, macOS, or Linux) with a modern web browser (Chrome or Firefox recommended)
- Power cord
- A free GitHub account (instructions will be provided 1 week prior to the workshop)
Provided by instructors:
-
- Pre-configured GitHub Codespace with tRIBS model executable, computational environment, Python tools, and input data, no software installation required
Course Outline
Introduction to new cyberinfrastructure for hydrologic modeling (Python, Jupyter Notebooks, GitHub Codespaces)
Comparisons of lumped/semi-distributed and fully-distributed watershed modeling approaches
Overview of the South Mountain Fan (SMF) watershed case study: project scoping, field reconnaissance, and data sources
Hands-on use of tRIBS for the SMF case study using GitHub Codespaces and Jupyter Notebooks
Additional Information:
All workshop materials are based on a tested curriculum developed for a graduate-level watershed modeling course at Arizona State University (Spring 2026). The materials include a project scoping study, a HEC-HMS modeling exercise, and a tRIBS modeling exercise, all using the South Mountain Fan watershed as a case study.
Key references:
- Raming, L.W., Vivoni, E.R., Mascaro, G., Cederstrom, C.J., et al. (2024). tRIBS v5.2: A multi-resolution, parallel platform for tributary hydrology in forest applications. Journal of Open Source Software, 9(101), 6747.
- Raming, L.W., Vivoni, E.R., Cederstrom, C.J., et al. (2025). pytRIBS: An open, modular, and reproducible Python-based framework for distributed hydrologic modeling. Environmental Modelling and Software, 188, 106432.
- Cederstrom, C.J., Vivoni, E.R., Mascaro, G., and Svoma, B. (2024). Forest thinning effects on watershed responses under warming. Water Resources Research. 60(6): e2023WR035627.
Instructor: Enrique R. Vivoni, Ph.D., P.E.
Dr. Vivoni is a leading researcher in watershed hydrology, eco-hydrology, and water resources management in arid and semiarid regions. He is one of the original developer of the tRIBS hydrologic model and has over 20 years of experience applying distributed models to watersheds across the southwestern U.S. and Mexico. He holds a Ph.D. in Hydrology and an M.S. in Environmental Fluid Mechanics from MIT. Dr. Vivoni is a Fellow of the American Geophysical Union, the American Association for the Advancement of Science, and the American Society of Civil Engineers. He is the founder of Tributary, a water technology startup translating research into tools for water managers. He has published over 200 peer-reviewed papers and has extensive experience in training, outreach, and stakeholder engagement.
Contact: [email protected], [email protected]
Instructor: Josh Cederstrom, M.S.
Josh Cederstrom specializes in distributed hydrologic modeling, technology development, and the application of open-source tools for watershed analysis. He holds an M.S. in Civil, Environmental, and Sustainable Engineering from Arizona State University, where his research focused on forest treatment effects on watershed responses under climate warming using the tRIBS model. He is the current developer of tRIBS and the pytRIBS Python package and has co-authored peer-reviewed publications in Water Resources Research, the Journal of Open Source Software, and Environmental Modelling and Software. Josh co-developed the course materials used in this workshop as part of a graduate-level watershed modeling course at ASU. Contact: [email protected], [email protected]
GitHub: github.com/tRIBS-Model