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受“厄尔尼诺”现象的影响,1998年气候异常,降雨中心长期停留在长江流域,导致3次持续大范围强降雨过程,形成了特大洪涝灾害。洪水过后,静心反思,长江洪涝灾害无不与生态破坏,环境恶化有关。长江上游地区历史上曾是森林茂密的地方,30年代初森林覆盖率为30％～50％。后因人类不合理的砍伐利用,致使森林面积锐减,水源涵养功能下降;长江中下游地区是淡水湖泊集中分布区,也是长江洪水主要调蓄区。解放以来有1/3以上的湖泊被围垦,围垦面积达1.3万km~2。1949年洞庭湖和鄱阳湖水面面积分别为4350km~2和5200km~2,至1997年仅为1210km~2和
Affected by the “El Nino” phenomenon, the anomalous climate and the rainfall center in 1998 persisted in the Yangtze River basin for a long time, resulting in three major and continuing heavy rainfalls and the formation of catastrophic floods. After the flood, meditation and reflection, the Yangtze River floods are all related to ecological damage and environmental degradation. The upper reaches of the Yangtze River region has historically been densely populated areas. In the early 1930s, the forest coverage was 30% to 50%. Due to unreasonable deforestation, the forest area plummeted and the water conservation function declined. The middle and lower reaches of the Yangtze River are the concentrated distribution areas of freshwater lakes and the main flood control reservoirs of the Yangtze River. Since liberation, more than a third of the lakes have been reclaimed and the reclaimed land area has reached 13,000 km ~ 2. The surface areas of Dongting Lake and Poyang Lake in 1949 were 4350km ~ 2 and 5200km ~ 2, respectively, and only 1210km ~ 2 in 1997