美国百年拆坝历史回顾

自1912年至今,美国拆坝历史已有百年之久,期间拆坝共计1108座。从拆坝数量、分布范围、坝高和坝龄等多个角度对这些闸坝的资料进行分析比较,得出不同年代美国的拆坝特点:1980年以前拆坝数量少,分布范围较小,但闸坝的负面影响及拆坝必要性开始被人们所认识;20世纪80年代以后拆坝数量和范围逐渐扩大,坝高仍小于20 m,拆坝原因以生态修复为主,且更加关注闸坝安全问题;20世纪90年代拆坝数量继续扩大,拆坝高度实现突破,编制完成《大坝及水电设施退役导则》;21世纪,拆坝数量、高度和长度都打破以往记录,被拆闸坝以混凝土坝为主且绝大多数超过了使用寿命。同时,分析表明,闸坝的拆除与当时的社会经济状况有着密不可分的联系。

Review of the dam removal in the last one hundred years in the United States

The history of dams' removal in the United States has been 100 years since 1912. During this period, the U.S. has dismantled 1108 dams. By analyzing and comparing the information such as the num-ber, region, heights, and age of these dams, we gave the features of dams' removal in the U.S. . Before the 1980s, the number and region of dams' removal is small, but people recognized the disadvantage of dams as well as the necessity of dams' removal. In the 1980s, the number and region of dams' removal have been increased. However,the height is still less than 20meters. And ecological restoration is the most important reason of dams' removal. As a result, the U.S. has paid more attention to the safety of dam. In the 1990s, the number of dams' removal continued to increase, and the U.S. achieved a breakthrough on the removed dams' height. In addition, Guidelines for Retirement of Dams and Hydroelectric Facilities has been finished. In the 21^st century, not only the number, but also the height and length of dams' removal has set new records. In this period, the concrete dam has been the main part that needs to be removed for the overlong service life. Besides, the result shows that there has been a connection between the situa-tions of dams'removal and the socioeconomic status.