How will climate change affect extreme events in the Pacific Northwest?

Collaborators:

• Project Lead: Oriana Chegwidden
• Data Scientist: Yifan Cheng
• Deborah Rose
• Conrad Koziol
• Jason Won
• Amy De Luna
• Tek Jung Mahat

The Problem

Climate change is expected to cause an increase in the frequency and severity of many extreme events. Here, we use a large dataset of deterministic streamflow projections under a variety of scenarios to explore the effects of climate change on droughts and floods at several locations along the Columbia River.

Application Example

This work can be used to identify areas with higher likelihoods of extreme events. This will allow water managers to plan for future changes using these tools at a fine-scale for each location.

Sample Data

Our data comes from the Computational Hydrology group at UW. We accessed it by pulling it from Hydroshare. The total files are approximately 20GB but we worked with only a few locations to develop tools that could be scaled up to the larger dataset. The subset of data that we analyzed can be accessed at https://www.hydroshare.org/resource/397df3ba3266415a83225dc4392414b2/

Specific Questions

• How do minimum, maximum, and mean flows change in this ensemble of climate change scenarios?
• What areas are most at risk to long-lasting low-flow scenarios under each of these models?
• What seasons have the greatest uncertainty and largest ranges of daily flows, such that water managers are operating under a very uncertain framework in preparing for floods?
• What tools can we use to scale up this analysis to multiple locations and model variables?

Existing Methods

Currently, managers are still developing tools to address questions under future climate scenarios. Previous studies have investigated these questions but we hope to expand the analyses to a large ensemble of scenarios and many locations.

Proposed Methods / Tools

We are using Jupyter Notebooks to analyze the data and plot it to visualize our findings. We used Hydroshare to share the large dataset with all collaborators. We developed a collective codebase using version control and GitHub in order to save the analysis scripts that we plan to apply to the larger dataset in the future.

Background Reading

Dittmer, K. (2013). Changing streamflow on Columbia Basin tribal lands - Climate change and salmon. Climatic Change 120: 627-641. DOI 10.1007/s10584-013-0745-0.

NOAA. (2014). Impacts of Climate Change on Columbia River Salmon. Retrieved from https://www.nwfsc.noaa.gov/assets/4/8153_09302014_105020_Crozier-Lit-Rev-Climate-Change-BIOP-2013.pdf