Preparedness and vulnerability reduction for various disasters in the world

A disaster is an unusual natural or human-made event or a combination of both, including an event caused by the failure of technological systems, which temporarily affects the human response capacity and affects societies, groups, and individuals. or natural environments causing massive damage, economic loss, disruption, injury, or loss of life.To conduct this review, IranMedex, Magiran, SID, PubMed, Scopus, Science-Direct, Cochrane, and Google Scholar databases were searched and articles related to disasters from 2000 onwards were selected. All articles were in English. The search found 68 articles, after studying them, 35 articles were discarded due to their irrelevance.Disasters can happen anywhere in the world and at any time. Disasters have severe effects on people's life, property, and environment. Research centers and organizations have investigated the phenomena of natural and unnatural disasters and have described and classified them based on different types and definitions. Disasters can be classified into three types: (1) natural (2) man-made (3) combined disastersDisasters are classified into three types: natural, man-made, and combined disasters. Three types of disasters are believed to cover all catastrophic events. No fixed definition of disaster has been accepted. Several criteria have been proposed to define disasters. Understanding the definitions, criteria, and types of disasters will help researchers and organizations in proper classification, good recording, and better analysis of disasters. Disasters have different characteristics and effects. However, disasters have one element in common and that is their intensity.