The Policy & Practice of Climate Change & Water

Risk assessment

Story Map Provides Tour of Climate-Related Hydrologic Risk Assessment for the California State Water Project

This article was written by Wyatt Arnold, Engineer, Water Resources at the California Department of Water Resources Climate Change Program.

To illuminate potential risks connected with the deeply uncertain future, planners with limited resources must often choose between two approaches. Option 1 provides a limited number of intensely bright yet narrowly focused spotlights (analogous to top-down analysis through downscaling of global climate models). Option 2 provides an unlimited number of glowing sticks, which may only softly brighten their surroundings, but cumulatively provide a more comprehensive perspective of the situation (analogous to bottom-up analysis through approaches such as
decision scaling). The second approach seems more worthwhile when tackling the wide range of climate changes projected for California within the next 30 years — from an overall increase of 1 to 4 degrees Celsius and from 20 percent less to 30 percent more overall precipitation.

In collaboration with researchers at the
Hydrosystems Research Group at the University of Massachusetts, Amherst, we adopted the second approach for assessing long-term and persistent hydrologic impacts of climate change on the California State Water Project (SWP). The SWP is a water storage and delivery system that extends more than two-thirds the length of California, serves 27 million people, and irrigates more than three quarters of a million acres of farmland.

We summarize results of our bottom-up, decision scaling study
in an online story map to facilitate access to the crucial information produced and the methods and thinking that went into its production.

Invitation to submit an abstract on "Practical Challenges in the Application of DMDU Methodologies to Climate Risk Assessment and Management"

Organizers have put out a call for abstracts for the session Practical Challenges in the Application of DMDU Methodologies to Climate Risk Assessment and Management at the upcoming Decision Making under Deep Uncertainty workshop from November 5-7. The session is convened by Casey Brown (University of Massachusetts - Amherst), Patrick Ray (University of Cincinnati), Umit Taner (University of Massachusetts - Amherst), and Ad Jeuken (Deltares). This session aims to bring in the expertise from both the research and practitioners community to discuss these practical challenges of adoption of DMDU methods, such as (but not exclusively) the World Bank Decision Tree Framework, Climate Risk Informed Decision Analysis (CRIDA), adaptation pathways, and RDM.