一引言中国是一个水患多发而又严重的国家。近两千年来,黄河中下游决口泛滥1593次,大改道26次,北到天津,南至淮阴,多次演出了“黄河夺淮”的历史悲剧。从1931-1949年的18年间,长江泛滥成灾11次,其中,1931年的洪灾,遍及湖北、湖南、江西、安徽、江苏、浙江、河南等7省共205个县,受灾面积15万平方公里,死亡14.5万多 I. INTRODUCTION China is a country with multiple and serious floods. In the past two thousand years, the Middle and Lower Reaches of the Yellow River have been flooding in 1593 times, with 26 major diversions, to the north in Tianjin and to Huaiyin in the south. Many times they have performed the historical tragedies of “capturing the Huaihe River from the Yellow River.” During the 18 years from 1931 to 1949, the Yangtze River flooded 11 times, of which 1931 floods covered 205 counties in 7 provinces including Hubei, Hunan, Jiangxi, Anhui, Jiangsu, Zhejiang and Henan, and the affected area was 150,000 square Km, more than 145,000 deaths