DRC-Disaster Research Center

Archived Studies


Population Composition, Geographic Distribution, and Natural Hazards: Vulnerability in the Coastal Regions of Puerto Rico

DRC Principal Investigator: Havidan Rodriguez
Faculty Researchers:Walter Diaz (Co-PI; University of Puerto Rico Mayaguez,) Aurelio Mercado (Co-PI)
Current Graduate Research Assistants: Jennifer Santos
Funding Agencies:NOAA Sea grant

Study Description

Given its geographic location and climatological conditions, Puerto Rico is highly susceptible to natural hazards (e.g., hurricanes, floods, tsunamis, landslides, earthquakes). Coastal or riverine flood areas and steep mountains characterize much of Puerto Rico. Hurricanes San Ciriaco (1899), San Felipe (1928), San Ciprián (1932), Santa Clara (1956), Hugo (1989), and Georges (1998) have had a significant social and economic impact on the Island’s population and economy. As a result of changing social and demographic patterns in Puerto Rico, there has been a significant increase in population density, in the proportion of the elderly and physically disabled population, and an increasing concentration of residents in flood and/or landslide prone areas, especially along the coastline. According to the Insurance Commissioner’s Office, as of June 2003, 160,000 families were living in flood prone areas in Puerto Rico, of which 43,568 (27.2%) did not have flood insurance. These factors have contributed to the increasing vulnerability to natural hazards on the island.

The primary goal of the proposed project is to understand how these and other factors contribute to the vulnerability of the Puerto Rican population living in coastal regions, how they have changed from 1990 to 2000, and how risk and vulnerability vary according to different demographic, social, and economic characteristics. This research project is a collaborative and interdisciplinary effort between the Disaster Research Center (DRC) at the University of Delaware, the Center for Applied Social Research (CASR) and the Physical Oceanography Laboratory in the Department of Marine Sciences, both at the University of Puerto Rico-Mayagüez.

To accomplish the aforementioned goals, we propose to:

  1. develop geographical maps of the coastal areas of Puerto Rico that will include detailed demographic and socioeconomic data of the resident population. GIS technology and existing storm surge and tsunami flood maps will be used as a starting point;
  2. conduct a census of emergency response agencies and other organizations and structures located in areas subject to coastal flooding;
  3. examine the determinants of vulnerability in the coastal regions of Puerto Rico and, using 1990 and 2000 Census data, determine how vulnerability in these regions has changed during a ten-year period.


  1. Completed digitizing Puerto Rico Storm Surge maps (except for two segments of the southern coast which are currently unavailable) into shape file formats for use in GIS applications. (see Figure 1 in the appendix for an example)
  2. Created GIS based maps integrating coastal flooding, 2000 census, topographic, built infrastructures and satellite data for all of Puerto Rico (Figures 2, 3, 4 and 5 and Table in the appendix 1 for examples.
  3. Integrated tsunami flooding data into the aforementioned maps. Using these maps we are calculating the amount of people and housing units threatened by tsunamis and storm surge in Puerto Rico at the census block level of resolution. This greatly reduces problems associated with aggregation effects present in previous work on these issued in the United States wherein Census Tracts were used for estimation (See Table 2 in the appendix for an example).
  4. Jenniffer Santos has completed the estimation of the first version of the aforementioned vulnerability to storm surge flooding for Puerto Rico. This is an additive index that includes 11 variables considered to be important determinants of social vulnerability by the literature on disasters (see Table 3 in the appendix).


  1. The infrastructure and maps developed as part of this effort have played an important role in the Puerto Rico Tsunami Hazard Mitigation Program, (Christa Von Hillerbrandt, PI) which led NOAA to declare Mayagüez as a Tsunami Ready City in march 2006. The same effort is currently in progress for the town of Añasco.
  2. Jenniffer Santos is completed her master’s thesis in Sociology at the University of Delaware using data and methods she developed as part of this project. She is also developing an interactive mapping tool in which we will also disseminate the findings and maps generated as part of this project.
  3. The development of the sampling frame is underway and will be the basis for a survey of evacuation behavior in Puerto Rico to be financed by the United States Army Corps of Engineers during FY 2006-07.