What occurs when a hazard results in significant impact on demographics or the environment?

The correct answer highlights the concept of a hazard event, which refers to the occurrence of a natural or man-made disaster that leads to significant impacts on demographics or the environment. This definition encompasses the phenomena such as earthquakes, floods, hurricanes, or industrial accidents, where the hazard itself manifests and starts to affect people and the environment. A hazard event is characterized by its capacity to cause disruption, damage, and potentially loss of life or property, thus often necessitating further actions such as disaster assessments or emergency responses in its aftermath.

Understanding this term is crucial in geography as it lays the foundation for studying how these hazards interact with human systems and natural environments, leading to broader implications for planning, response, and recovery strategies in vulnerable areas.