美国地广人稀,江河密布,是一个洪灾多发的国家,其受洪水威胁的国土面积约占总面积的7%,受影响人口达到3000多万(占总人口的12%)。因而,洪水灾害是美国政府最为关注的自然灾害。与人类治水的发展历程相似,美国治水大体也经历了以解决人们生存安全和基本生活需求为主要目标的 With sparsely populated and dense rivers, the United States is a flood-prone country. Its flood-threatened land area accounts for about 7% of the total area and the affected population reaches more than 30 million (12% of the total population). As a result, flood disasters are the natural catastrophe most concerned by the U.S. government. Similar to the history of water-control in mankind, the flood control in the United States generally has also undergone the major objective of solving the problems of people’s livelihood security and basic living needs