ERTH 2415 Lecture Notes - Lecture 1: Natural Disaster, Return Period, Water Cycle
11 Jul 2017
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Document Summary
Natural disaster an extreme natural event in which a large amount of energy is released in a short time with catastrophic consequences for life and infrastructure in the vicinity. Greek astronomer believed connection between natural disasters and unfavourable positioning of planets in the sky. Natural disaster attributes (impact on society: significant causalities, destructive impact on infrastructure, disruption to society, large economic losses, call for exterior help, media coverage, government involvement. Natural hazards a source of danger that exists in the environment and that has the potential to cause harm. Natural hazards become natural disasters when they intersect with vulnerable communities. Natural hazards are inevitable but natural disasters are not. Natural disasters occur when hazard meets vulnerability (blaikie. Vulnerability- likelihood that a community will suffer, both in terms of fatalities and physical damage, when exposed to hazards in the environment. Frequency- number of similar events per unit time. Return period- length of time between similar events.
