Open-File Report 2007–1255
U.S. GEOLOGICAL SURVEY
Open-File Report 2007–1255
Back to Table of Contents
To accomplish our mission of applying the best science to improve disaster resiliency, we must
Natural hazard information is useful when it is factored into decision-making about risk reduction strategies. USGS activities will increase our understanding of the framework of hazard possibilities, vulnerable environments, community responses, and associated risk reduction options. The vulnerable environment is in part created by humans, but is also natural—the soils, geology, hydrology, and ecology. Activities will be prioritized and carried out in order to fill gaps in the scientific knowledge base, which can help to improve resiliency. We aim to gain an understanding of the relations between human actions and environmental vulnerabilities and inform decision makers about possible risk reduction measures.
The Multi-Hazards Demonstration Project is based on existing hazards research programs of the U.S. Geological Survey. The USGS role varies for the different hazards.
Earthquakes. The USGS has statutory responsibility to assess earthquake hazards for the Nation, monitor seismic activity and issue alerts, and conduct targeted research into earthquake processes and effects.
Landslides. The USGS has statutory responsibility to assess and issue warnings of landslide hazards for the Nation and conducts applied research in support of that responsibility.
Floods. The USGS has responsibility to monitor stream levels for use by NOAA in flood warnings and to conduct research on flood inundation and hydrology.
Tsunamis. The USGS assesses offshore geologic faults and landslides for tsunami generation potential, conducts research in tsunami generation, and provides global seismic data to NOAA for use in tsunami warnings and mitigation.
Fires. The USGS provides geospatial support to land-management agencies and conducts research in fire ecology and response of ecologic systems to fires.
Coastal erosion. The USGS conducts research in marine geology on susceptibility to coastal erosion.
Figure 2 shows the schematic relationships of the need for and flow of information in making decisions for risk reduction. Possible actions are shown in gold boxes and can take place either before or during and immediately after an event. The variables of the hazard system are shown in blue ovals. The hazard (for example, fire, earthquake, flood, etc.) has some probability of occurring with some magnitude, location, and other characteristics. It acts upon an environment with some susceptibility to the hazard. Most risk-reduction strategies are applied to this environment, such as compacting soils to reduce shaking, planting grass to stop erosion, or retrofitting buildings to prevent damage. The effect of each of these decisions on reducing losses can be determined through scientific study but also depends on the state of the environmental system. A second set of actions is undertaken during or after the event, such as fire fighting, and search and rescue. All of these elements affect each other and result in certain outcomes, shown in purple, of economic losses, casualties, and ecologic damage.
The decisions on the left side of the diagram are being made by different individuals and communities in southern California. The goal of the Multi-Hazards Demonstration Project is to understand the characteristics and relationships among the elements on the right so as to better predict the effects of the various risk reduction strategies and to communicate this information to those making the decisions. This information will provide critical support for improving strategies that will actively reduce losses. The elements and interdependencies will be captured in an influence diagram (modeled after that shown in figure 2) for each hazard that we are studying: earthquakes, tsunamis, wildfires, landslides, floods, and coastal erosion.
These hazards also are interdependent (table 1). An earthquake can immediately trigger fires, and a fire makes an area more susceptible to debris flows. Moreover, the risk-reduction strategy for one hazard may reduce or even aggravate some other hazard. The Multi-Hazards Demonstration Project proposes to investigate and communicate the relationships among the hazards, how they trigger each other, and how the risk reduction strategies interact.
To accomplish these multi-faceted tasks, the Multi-Hazards Demonstration Project will be organized around four working groups. Three of the groups—Earthquakes and Tsunamis (ET), Fire and Debris Flows (FD), and Winter Storm Events (WS)—will focus on the research of particular hazards and some of the interrelationships. The hazards have been grouped by the most direct connections among events. The fourth group, Integration and Implementation Interface (I-cubed), will support the interface with the community as well as develop the risk analysis model described schematically in the influence diagram (figure 2). This risk analysis model provides the backbone of the framework for conceptualizing the full range of activities of the Multi-Hazards Demonstration Project and its relationship to southern California decision making. As we move to concrete products that can actually be used, we can envision these as subsets of the bigger framework.
On the basis of input from external participants attending workshops during the winter of 2006, we have identified four initial priority areas for community support. These are our first-pass priorities and will be modified as necessary throughout the duration of the project. First is the integration of mapped hazards and expected consequences into risk and decision-making tools that individuals and communities can use to evaluate alternative actions. The development of analytical and numerical tools to access the information in this system will be a key aspect of the project framework.
Second is helping decision makers to develop planning scenarios and quantifying anticipated consequences of future events so they can do a better job of emergency preparedness and planning. These scenarios are needed for all the hazards and need to convey the range of anticipated consequences, including the social and economic outcomes. This can be understood as one specific path through the influence diagram by setting the hazard probability to one for only one specific event.
Third is to improve upon the mapping of urban hazards. Maps are needed that specifically assess the probabilities of different hazard occurrence and their likely magnitude. For example: Is the threat to a given site greater for flooding or landslides? Where is earthquake shaking amplification most severe? These are a geographical representation of the upper part of the influence diagram, the hazard and environment susceptibility, for all the hazards.
|Relationship of Working Groups to U.S. Geological Survey Science Centers and Programs|
|Working group||Science centers of most participants||Primary funding programs|
|Integration and Implementation Interface||All science centers||All programs|
|Earthquakes and Tsunamis||Earthquake Hazards, Western Coastal and Marine||Earthquake Hazards, Coastal and Marine Geology|
|Fire and Debris Flows||Geologic Hazards, Western Ecologic Research Center, California Water Science Center, Earth Resources Observation System (EROS) Science Center||Landslide Hazards, Ecosystems, Geographic Analysis and Monitoring, Land Remote Sensing|
|Winter Storm Events||California Water Science Center, Geologic Hazards, Western Coastal and Marine||National Streamflow Information, Landslide Hazards, Geographic Analysis and Moni-toring, Coastal and Marine Geology|
The fourth priority is providing real-time information. For some hazards, knowing the ongoing processes can help mitigate the consequences. For instance, real-time debris-flow risk (determined from short-term rainfall prediction and geologic susceptibility) can be used to target evacuations. Near-real-time earthquake shaking maps can be used to guide rescue operations to the most heavily shaken areas. Participants also expressed the need for products that will allow them to postulate and evaluate choices for a risk-reduction strategy. This will be support for the response decision box in the influence diagram.
Activities are being designed with our existing and new partners to accelerate the development and dissemination of information. This will include working with partners from academic institutions to support research that will lead to future generations of tools that communities can use. We will also work with the earth observation networks of the USGS (seismic, geodetic, ground movement, stream gages, and land cover) and partners in southern California to ensure their continued and enhanced operations. We will work together to develop a new generation of monitoring products that provide greater situational awareness for emergency responders.
Back to Table of Contents