Science Center Objects

The SAFRR project’s second scenario, called ARkStorm, addresses massive U.S. West Coast storms analogous to those that devastated California in 1861–62. Storms of this magnitude are projected to become more frequent and intense as a result of climate change. The SAFRR project assembled experts from scientific research agencies to design the large, but scientifically plausible, hypothetical storm scenario hitting both northern and southern California. The wind, precipitation and flooding, and coastal hazards were translated into physical, environmental, social, and economic damages to provide emergency responders, resource managers, and the public a realistic assessment of what is historically possible.

The ARkStorm scenario was released at the ARkStorm Summit, a two day conference in Sacramento (January 2011), where 250 invited guests from the public and private sector joined together to take action as a result of the scenario’s findings. 

Hazards Societal Consequences and Risk Communication Contributions

Anne Wein coordinated analyses of exposed populations, agricultural impacts (leveraging the Delta Risk Management Strategy methods) and economic consequences (figs. 1 and 2) and sensitivity analyses of damages, reconstruction funding, and resilience strategies (with university collaborators). WGSC team members (Jeff Peters, Jamie Jones, Rachel Sleeter, a visiting scholar, and a contractor) provided the GIS and mapping support for analyses of highway damages and capacity, numbers and profiles of flooded populations (fig. 3), and flooded agricultural lands (fig. 4).

Graph of estimated ARkStorm impacts

Figures 1 and 2. ARkStorm impacts on the trajectory of semi-annual real GDP (1) and semi-annual losses and recovery relative to pre-event GDP (2). (Credit: Anne Wein, USGS. Public domain.)

Graph of ARkStorm population exposure in rural and urban areas

Figure 3. Difference in population concentrations in and out of the ARkStorm flood zone. Note: counties ordered by percentage of the county population that is flooded, with only statistically significant difference in population proportions displayed. (Credit: Anne Wein, USGS. Public domain.)

Map of ARkStorm agricultural loss estimates

Figure 4. ARkStorm flood duration (days) and proportions of estimated agriculture losses where perennial crop losses dominate the losses. * Delta Island inset shows results for islands with losses for two years only. (Credit: Jeff Peters, USGS. Public domain.)