各种自然灾害正威胁着人类的生存和发展。我国是一个自然灾害频繁、受害严重的国家。半个世纪以来,虽年年兴修水利,新建防汛减灾工程,成效显著,但因灾害群发,强度又大,加上人类活动的社会因素,自然灾害造成的损失日趋严重。去冬今春以来,因受厄尔尼诺影响,气候变化异常,我国北方持续干旱,南方降雨量明显偏多,入汛时间比常年提前一个多月。3月上旬,江西赣江上游发生了历史上第三大洪水,湖南湘江、福建闽江发生历史同期最大洪水,广东北江出现历史同期第三大洪水。6月中旬,除重庆暴 Various kinds of natural disasters are threatening the survival and development of mankind. Our country is a country with frequent natural disasters and serious victimization. Although water conservancy has been built every year for half a century, the flood control and disaster reduction project has been completed with remarkable results. However, due to the mass and intensity of disasters and the social factors of human activities, losses caused by natural disasters have become increasingly serious. Since the winter and spring this year, due to the influence of El Niño, the climate change is anomalous. The northern part of our country has a continuous drought. The rainfall in the south is obviously more. The flood time is more than a month ahead of normal. In early March, the third largest flood in history took place in the upper reaches of Ganjiang River in Jiangxi Province. The largest flood of the same period occurred in Xiangjiang River in Hunan Province and Minjiang River in Fujian Province, and the third flood in the same period in Beijiang River of Guangdong Province. In mid-June, except Chongqing storm