Tsunami-evacuation sign in the city of Nehalem, Oregon
The community of Orting, Washington in a lahar-hazard zone beneath Mount Rainier
A vulnerability assessment training for local emergency managers in Oregon
Our country faces a wide array of natural hazards that threaten its safety, security, economic well-being, and natural resources. To minimize future losses, communities need a clear understanding of how they are vulnerable to natural hazards and of strategies for increasing their resilience. Vulnerability and resilience are influenced by (1) how communities choose to use hazard-prone land, (2) pre-existing socioeconomic conditions, (3) likely future patterns of land change, and (4) current efforts to reduce and manage risks.
The objective of this project is to develop new ways of assessing and communicating community vulnerability and resilience to natural hazards. This work supports core elements of the USGS mission that focus on understanding land change and minimizing life loss and property damage from natural disasters. The project has completed work on all types of natural hazards, from sudden-onset extreme events (earthquakes, tsunamis, volcano lahars) to chronic events (sea level rise, coastal erosion).
Throughout the various research efforts and assessments, we have developed or improved methods for understanding and communicating societal vulnerability to natural hazards. This project has produced techniques-related articles on the following topics:
Geographical analysis – We use geographic information system (GIS) tools to estimate variations in community exposure of populations, land uses, infrastructures, and economic activities to natural hazards in various States. Exposure assessments have been completed based on maximum hazard zones, scenario-based zones, and comparisons of multiple hazard scenarios. GIS-based statistical analysis is also used to identify variations in demographic sensitivity across a community to natural hazards. We have also applied GIS tools to identify areas in a community with high hazards and societal assets, to demonstrate how landcover data can be used to characterize regional exposure to hazards and to improve population maps.
Spatial modeling – We use GIS to model pedestrian evacuation out of hazard zones, based on landcover, elevation, hazard, and population data. Results help local officials understand where successful evacuations are possible and where vertical-evacuation refuges may be warranted to help save lives. We also have developed GIS methods for helping to site vertical-evacuation refuges, as well as look at past disasters to compare fatality patterns and evacuation potential. To help others do their own pedestrian-evacuation modeling, we’ve created a GIS tool.
Stakeholder surveys – Community vulnerability to hazards cannot be completely understood using only GIS tools and socioeconomic data. Public perceptions and priorities related to hazards are also important elements. Therefore, we use community-based assessment workshops, community recovery forums, and surveys to better understand the human element in vulnerability.
Public engagement - An important part of this project has been training others in our methods so that they can carry out their own assessments. There have been several efforts of the years to share results and methods with emergency managers, local officials, the general public and students, such as “train-the-trainer” workshops related to tsunami preparedness, vulnerability assessment workshops for local emergency managers, and graduate short courses.