Coastal Services Center

For three days in January 2004, strong winds and heavy rains from a near miss by Hurricane Heta displaced more than 3,000 families from their homes and left the island of Tutuila, American Samoa, with no electricity or water.

In addition to hurricanes, Tutuila, the largest and most populated of the seven South Pacific islands that make up the U.S. territory of American Samoa, is vulnerable to tsunamis, flooding, landslides, and earthquakes.

But the public often is unaware of the natural hazard risks when they apply to the American Samoa Coastal Management Program for building and development permits. Finding a quick and easy way to visually show developers the range of hazards a proposal might face was a critical planning and permitting need for the islands' coastal program, says manager Genevieve Brighouse.

The solution was a Web-based, "point and click" geographic information system (GIS) tool that allows the coastal program staff and permit applicants to rapidly and accurately identify potential hazard risks for any location on Tutuila. This location-specific information is provided to the user in the form of a text summary, as well as a map.

With this information in hand, Brighouse says, developers now "understand what it will entail to produce a proposal that will be acceptable in terms of the types of hazards it will be exposed to."

The tool is so simple that with only a little bit of technical expertise it could easily be modified for other coastal areas and issues.

Part of the Plan

The Tutuila Hazard Assessment Tool (T-HAT) was the result of a partnership between the American Samoa Coastal Management Program, which is part of the American Samoa Department of Commerce, and the National Oceanic and Atmospheric Administration's (NOAA) Pacific Services Center and Coastal Services Center. Using Internet Explorer, this ArcIMS-based tool can be viewed at www.csc.noaa.gov/t_hat/.

T-HAT makes use of GIS hazard data used in American Samoa's recently completed Hazard Mitigation Plan, which the Disaster Mitigation Act of 2000 requires states and territories to complete to receive Federal Emergency Management Agency (FEMA) funding for hazards mitigation.

"This was a really good opportunity to take existing information that was developed for another purpose and repackage it with a different focus to meet a different user's needs," says John Marra, a Perot Systems Government Services natural hazards specialist contracting with the NOAA Pacific Services Center in Hawaii.

To make the data easily accessible, custom tools were built to query the data for site-specific hazard information, explains Russell Jackson, NOAA Coastal Services Center coastal hazards specialist.

It would not take much, Jackson adds, for coastal managers in other areas to create their own hazard assessment tool. "It would be very simple to take this shell and insert your own data, and you would have the tool. All you need to be able to use it is a Web browser."

Marra notes that the tool also could be expanded to include more than just hazards data. "The same tool could identify wetlands or other sensitive resources—whatever you have the need and data for."

Putting It to Use

In four easy steps, T-HAT allows users to zoom to a village, select a hazard to identify, and, by clicking on the map, obtain the potential hazard risks for that specific location, Marra explains.

The first step is to "Select Your Village" from a drop-down menu. In the second step, "Select a Hazard to Identify," users choose a hazard from a drop-down list that includes tsunamis, flooding, landslides, earthquakes, or all hazards.

At this point, step three, the user then clicks the "ID Hazard" button, which zooms the map to the selected village and displays the appropriate hazard layer.

Finally, in step four, the user clicks on the specific proposal site, and information about the potential hazards affecting the site is provided. By clicking on the "More Information" button, users can learn the source of the data.

"When the computer shows them their proposal is in a landslide area, it really brings the message home," says Brighouse. "We needed to make that connection. The public did not understand the risks. They sometimes think the government has a hidden agenda, and they often wanted more information than we could easily provide. Now we can sit down with them and visually show them the hazards and that there is data to back it up."

She adds, "This is a critical tool for us."

The Next Wave

Since the American Samoa Coastal Program began using T-HAT last October, the island has experienced a "very serious landslide," and a massive tsunami struck Asia the day after Christmas.

"This tool has been very timely," Brighouse says. The vulnerability of the islands to natural hazards has "really been brought home."

Brighouse says they plan to enhance the tool, which is already used daily by coastal program staff members, by integrating additional data layers and expanding its application to include outreach and education efforts. Plans also are underway to educate other American Samoan government agencies about the tool so that the public receives a "consistent message, no matter if it is from us or public works."

Marra notes that by expanding the tool's data layers, such as data on historic losses and demographics, it could be vital in the planning and response to a tsunami or other natural disaster. "It could be used by emergency managers to prioritize areas where assistance is needed to facilitate evacuation should an event occur, or prior to the event for targeting the dissemination of educational materials."

Brighouse recommends T-HAT for all coastal managers who have permitting abilities, particularly those on other islands. "I would strongly recommend others look into this as a model for addressing hurricanes, flooding, landslides—all the immediate threats that are common to all of us."

To view the Tutuila Hazard Assessment Tool (T-HAT), point your browser to www.csc.noaa.gov/t_hat/ (use Internet Explorer). For more information on the use of the tool, contact Genevieve Brighouse at (684) 633-5155 or Gene.Brighouse@noaa.gov. For technical questions, contact Russell Jackson at (843) 740-1188 or Russell.Jackson@noaa.gov.