Introduction to Models and Risk Assessment

Models, whether they be qualitative, quantitative, or a combination of both, play a fundamental role in risk assessment. Since the initial application of single-point deterministic analyses in the 1990s, ecological risk assessments have progressed to consider multi-stressor and multi-outcome assessments in dynamic environments. These advances have demanded an increase in the sophistication of the models we use, while meeting users’ requirements of greater realism and transparency in decision-making processes. Notwithstanding these advances, the premise of risk and risk assessments remains unchanged. Risk is the chance, within a time frame, of an adverse event occurring with specific consequences, and risk assessment is a process used to collect, organize, integrate, and analyze information for use in a planning environment, where the outcome is the analysis and prioritization of risks or hazards to a stated objective. The objective of a risk assessment is to improve the understanding of the risks for a given system, and to guide the identification and implementation of appropriate risk management strategies to minimise, monitor, and control the probability or impact of adverse events.