20世纪中期，长江流域的人口增长进入了一个前所未有的新时期。持续增长的数——”亿人的生存需要，终于把这条伟大的长江变成了第二条黄河。长江在这100年里生态平衡被严重破坏了。据1957年调查统计，长江流域森林覆盖率为22％，水土流失面积3638万平方公里，占流域总面积的20 The mid-20th century, the Yangtze River valley population growth has entered an unprecedented new period. The number of sustained growth - "the living needs of millions of people, and finally the great Yangtze River has become the second Yellow River in the ecological balance of 100 years has been severely damaged.According to the 1957 survey, the Yangtze River forests The coverage rate is 22%, and the soil erosion area is 36.38 million square kilometers, accounting for 20% of the total basin area