Oregon Natural Hazards Mitigation Plan

Oregon Department of Land Conservation and Development
Posted on: 5/17/2019 - Updated on: 5/17/2019

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The purpose of the Oregon NHMP Risk Assessment is to identify and characterize Oregon’s natural hazards, determine which jurisdictions are most vulnerable to each hazard and estimate potential losses to vulnerable structures and infrastructure and to state facilities from those hazards.

Assessing the state’s level of risk involves three components: characterizing natural hazards, assessing vulnerabilities, and analyzing risk. Characterization involves determining cause and characteristics, documenting historic events, and evaluating future probability of occurrence.

A vulnerability assessment combines information from the hazard characterization with an inventory of the existing (or planned) property and population exposed to a hazard, and attempts to predict how different types of property and population groups will be affected by each hazard.

A risk analysis involves estimating the damages, injuries, and costs likely to be incurred in a geographic area over a period of time. Risk has two measurable components: (a) the magnitude of the harm that may result, defined through vulnerability assessments; and (b) the likelihood or probability of the harm occurring. Together, the Oregon Hazards and Oregon Vulnerabilities sections form the risk analysis at the state level.

Regional risk assessments begin with a description of the region’s natural environment, demographics, economy, infrastructure, and built environment followed by a region-specific hazard characterization, vulnerability assessment, and risk analysis.