The Assessment Framework
The definitions for “risk” and “hazard” in forest pest management can be confusing and contradictory. Rather than reconcile the various definitions of risk and hazard we use the following construct.
When assessing risk as it relates to forest health, risk is often composed of two parts: the probability of a forest being attacked (susceptibility) and the probability of resulting tree mortality (vulnerability) (Mott 1963). Characterizing the spatially explicit probability of insect and disease activity requires spatially explicit quantitative data. However, because such data are often lacking at regional, national, and local levels, we define risk as the potential for harm due to exposure to an agent(s). Also, we draw the distinction between susceptibility and vulnerability (Mott 1963), but in the context of potential rather than probability.
Our threshold value for mapping risk is defined as the expectation that, without remediation, over the next 15 years 25 percent or more of standing live basal area (BA) in trees greater than 1 inch in diameter will die due to insects and diseases. The threshold value for mapping insect and disease risk is independent of the GIS framework discussed in the remainder of this paper. Therefore, the framework can support any threshold.
- A Conceptual Overview of a National Risk Assessment Framework : Risk assessment framework provides a conceptual overview of the risk-assessment process discussed.
- A GIS-Based Multicriteria National Risk Assessment Framework: a Five-Step Process : The risk assessment framework used to construct NIDRM is best explained using a hypothetical example.
- Modeling at Multiple Scales/Resolutions : Once a model has been constructed in ESRI ArcView 3.x Spatial Analyst 2.x ModelBuilder, models can be rerun at multiple scales.
Encyclopedia ID: p3415
