Digital Coast

Issue

The U.S. territory of American Samoa, comprising seven islands in the South Pacific Ocean, is at risk from a variety of natural hazards. Often these hazards occur simultaneously, resulting in many different types of damage to property, resources, and life. While unable to regulate and stop the occurrence of natural hazards, those at risk can take action to prepare for and mitigate the effects of these hazards. The Tutuila Hazard Assessment Template (T-HAT) was developed to facilitate the identification of potential multi-hazard risk areas for any location on the main island of Tutuila.

Process

T-HAT is a lightweight Internet mapping application that uses GIS hazard data from American Samoa's Hazard Mitigation Plan (collected from the Pacific Disaster Center) and the American Samoa GIS User Group. The user group consists of GIS professionals who lead the development and organization of American Samoa’s GIS data. The data were integrated into an Internet mapping environment with custom tools for querying the data for hazard information.

The hazards examined in the tool are floods, landslides, earthquakes, and tsunami. Supporting GIS base data are villages, roads, buildings, and the island’s shoreline. The purpose of the base data is to help users locate their area or location of interest. In the tool, users have the ability to zoom in to a village, select a hazard to identify, and by clicking in the map on a specific location, receive a potential hazard risk for that location.

Impact

This tool is helping the American Samoa Coastal Management Program and its constituents evaluate requests for permits in light of potential hazard risks and to plan for the effects of hazards when managing the coast. The T-HAT is representative of what can be done with existing hazard mitigation data in the Pacific Islands. It uses a portable method that, with appropriate GIS data, can be implemented on other Pacific islands.

The T-HAT user interface - areas shaded in red denote high tsunami risk