Natural hazard natural hazards and anthropic processes. For example, groundwater abstraction may trigger groundwater-related subsidence. Effective hazard analysis in any given area (e.g., for the purposes of disaster risk reduction) should ideally include an examination of all relevant hazards and their interactions. To be of most use for risk reduction, hazard analysis should be extended to risk assessment wherein the vulnerability of the built environment to each of the hazards is taken into account. This step is well developed for seismic risk, where the possible effect of future earthquakes on structures and infrastructure is assessed, as well as for risk from extreme
Prevalence effect of success and the stakes are low. Some searches combine low prevalence with high stakes; medical screenings such as mammography or cytopathology, is an important search for a target rarely present (typically under one percent). Missing a rare target, such as a weapon smuggled onto an airplane, may have serious consequences. The prevalence effect is influenced by top-down control of a future prospect or the bottom-up priming of past experience. Top-down refers to the expectation effect: knowledge of what will happen next. The bottom-up, repetition effect is produced by the sharing of properties by current and preceding stimuli. Observers may