February 21, 2014
A new report from the RAND Corporation highlights how policymakers can better develop strategies to restore and maintain coastal landscapes and reduce risks to coastal communities from storms like Hurricane Sandy and Hurricane Katrina.
The report describes two key analytic tools that can be used to evaluate how coastal protection and restoration decisions made now will play out over time, even given an uncertain future. For example, a community weighing whether to implement a marsh-building project now or in the future can use the tool to see how the project fares against different rates of rising sea levels over time.
“As coastal communities continue to grow and develop, it becomes increasingly important for policymakers to develop proactive, robust and evidence-based plans to manage increasing coastal risks, including flooding from storm surges,” said David Groves, lead author of the study and a policy researcher at RAND, a nonprofit research organization. “The tools developed at RAND and applied in Louisiana can help government officials and others prepare for future threats, even when the future is so uncertain.”
The populations of U.S. coastal communities have grown by more than 45 percent between 1970 and 2010, while at the same time coastal lands have been degraded by rising sea levels, subsidence and human activities. These factors create vulnerability in communities when major storms hit.
In 2012, Louisiana's Coastal Protection and Restoration Authority issued its groundbreaking “Louisiana's Comprehensive Master Plan for a Sustainable Coast,” a $50 billion strategy for reducing flood risk and coastal land loss. The master plan outlines a series of risk-reduction and restoration projects to be adopted over the next 50 years to reduce hurricane flood risk in coastal communities and restore Louisiana's coast.
RAND researchers supported the authority's efforts by developing a structured analytical framework for evaluating future risks and comparing alternative approaches for reducing those risks. RAND developed a modeling tool to help decision-makers choose among investment strategies, and a flood risk model to estimate property and other damages associated with storm surge and flooding.
The Coastal Louisiana Risk Assessment Model is designed to provide a realistic picture of coastal flood damage in many possible future conditions, with different rates of sea-level rise or economic growth, said Jordan Fischbach, coauthor of the report and a RAND policy researcher.
“The model provided Louisiana with flexibility, allowing the state to evaluate the potential risk-reduction benefits from hundreds of proposed projects across different scenarios,” Fischbach said. “The framework and models can be applied to other coastal regions.”
Groves said the new RAND study can help policymakers in other coastal regions better understand their options to reduce flood risks, rebuild or restore coastal environments, and more-generally increase the resilience of developed coastlines.
The RAND tools do not tell policymakers which options to choose. Instead, they allow policymakers to visualize the trade-offs in choosing one set of options over another. For example, the tool shows how a plan that emphasizes coastal land building might stop land loss, but could also lead to a loss of habitat for saltwater aquatic species.
In using these tools, the authors explain that policymakers should keep three things in mind. First, public participation is essential throughout the process, both to incorporate local knowledge and ensure the credibility of the process. Second, the technical analysis should inform deliberations by decision makers, not provide a single answer to be “sold” to constituents. Finally, a successful, sustainable long-term strategy must be robust and adaptive — it should include near-term investments that provide a strong foundation for future decisions that can be made in response to conditions that develop over time.
The study, “Strengthening Coastal Planning: How Coastal Regions Could Benefit from Louisiana's Planning and Analysis Framework” can be found at www.rand.org. Other authors of the study include Debra Knopman, David R. Johnson and Kate Giglio.
Research for the study was conducted in the Environment, Energy and Economic Development Program within the RAND Justice, Infrastructure and Environment division. The division's mission is to improve the development, operation, use and protection of society's essential physical assets and natural resources and to enhance the related social assets of safety and security of individuals in transit and in their workplaces and communities.