巨灾是指对人民生命财产造成特别巨大的破坏损失,对区域或国家经济社会产生严重影响的自然灾害事件。发生巨变的自然灾害主要包括:大地震与地震海啸、特大洪水、特大风暴潮。巨灾的基本特点是:灾害活动规模或强度巨大,受灾面积达一个省或几个、十几个省(区、市),受灾人口达几千万 Catastrophe refers to natural disasters that have caused particularly tremendous damage to people’s lives and property, and have a serious impact on the economy and society of a region or a country. The major natural disasters include: major earthquakes and earthquakes, tsunamis, catastrophic floods and catastrophic storm surges. The basic characteristics of catastrophe are: a large scale or intensity of disasters, the affected area of ​​a province or a few, a dozen provinces (autonomous regions and municipalities), the affected population of tens of millions