Coastal Hazards, Public Education and Risk Perception in Puerto Rico: Tsunamis and Hurricanes

The Caribbean has a history of exposure to both destructive hurricanes and tsunamis. The risk presented by hurricanes is familiar to most observers as the region is frequently exposed to them. Significant tsunami events, though much less frequent than hurricanes, do occur with some regularity as, for example, the Virgin Islands (1867), Puerto Rico (1918) and the Dominican Republic (1946). Tsunamis originating around Puerto Rico are a near-field hazard for the region as they can reach coastal areas within minutes of an earthquake or submarine landslide. To mitigate these risks to coastal communities, the Puerto Rico Tsunami Warning and Mitigation Program (PRTWMP) was established in 2000 with funding from FEMA, the University of Puerto Rico (UPR) and the PR State Emergency Management Agency (PRSEMA). This was further spurred by the massive Indonesian tsunami event of 2004. The Puerto Rico Seismic Network (PRSN) has led the implementation of NOAA's TsunamiReady Program (TR) on the Island and, to date, 33 of 44 tsunami exposed municipalities are now TR recognized. TR has made a concerted and systematic effort to educate both the public and governmental officials on the tsunami threat and how to respond to it.

However, even though major hurricane impacts are higher probability events than major tsunamis in Puerto Rico, and many more people are exposed to threats associated with them (e.g. over 300,000 persons are exposed to storm surge flooding while approximately 78,000 are exposed to tsunami flooding), there is no similar ongoing and comprehensive effort similar to PRTWMP for hurricanes.

This paper will highlight findings from 4 National Tsunami Hazard Mitigation Program supported sample surveys of areas exposed to tsunami and other coastal hazards, including hurricane storm surge flooding, to assess the effectiveness of TR/NTHMP outreach to educate the public on tsunami risk and on how to prepare and respond to it, as well as how this relates to perceptions of other coastal hazards such as hurricane storm surge flooding. The 4 surveys were conducted between 2009-2011 and have a total sample size of 2000 respondents. The sampling was designed to allow us to compare 3 groups of interest: those living in areas exposed to tsunami flooding within TR communities; those living in tsunami exposed areas but NOT within TR communities; and those living in areas exposed to storm surge flooding but NOT tsunami flooding. Furthermore, since the surveys were carried out over 3 years, we can also observe change over time. We find that TR/NTHMP efforts have resulted in a substantial increase in both tsunami knowledge and risk perception. However, impacts on behavior relating to mitigation and preparation are smaller. Furthermore, the increase in tsunami knowledge and risk perception seems to be associated to decreased risk perception related to hurricane storm surge exposure.. This effort serves as an example of the multidisciplinary collaboration between physical and social scientists needed to increase the effectiveness and value of scientific knowledge as a tool to save lives and mitigate damages from natural hazards.