洞庭湖退田还湖及其生态恢复过程分析

Analysis on the Restoration and Ecological Recovery of DongtingLake by Stopping Cultivation

洞庭湖曾是我国第一大淡水湖泊,盛期面积达6000km2以上,具有调蓄长江中游洪水的巨大生态服务功能.但经过近百年来的沧桑变迁,湖泊发生了巨大变化,由于泥沙的严重淤积和围湖垦殖活动,湖泊面积已萎缩至2625km2,为我国第二大淡水湖泊.湖泊萎缩削弱了其生态服务功能,并由此引发了江湖洪水愈演愈烈的形势.1998年长江流域洪涝灾害之后,中国政府及时提出了"退田还湖"等洪水治理的32字指导原则,湖区各地随即积极开展了"退田还湖、平垸行洪和移民建镇"等工程.本文针对湖区退田还湖双退堤垸的生态恢复过程,选择湖南省汉寿县的青山垸进行了跟踪研究.结果显示了湖泊湿地恢复的阶段性特征,并为我国日益严重的湖泊富营养化问题的治理,提供了新的途径和可供参考的科学依据.

Dongting lake, which had been the largest fresh water lake of china with an area of more than 6000 km2, plays a significant role in adjusting runoff of the middle Yangtze river. Dongting Lake has dramatically changed for the past 100 years, of which the area has reduced to 2625km2 up to now, and becomes the second largest fresh water lake for the serious siltation of mud and sand. The reduction of the area results in the diminishment of the ecological function, and also leads to the more serious flood and degeneration of the wetlands. The guide principles of floods control of the Yangtze catchment, which refers to restoring lake by stopping cultivation, was implemented by the central government after the flood disaster in 1998, and the projects including ' restoring lakes by stopping cultivation etc have been carried out in the area of the Dongting Lake. In the article, the process of ecological restoration of Dongting Lake by stopping cultivation is analysed in Han-shou County of Hunan Province as the experimental area. The results present a staggered feature of restoration of the wetlands, and offer new way and scientific experiemental basis to harness the problem of eutrophication in lakes and wetlands.