【摘要】 <正> 洞庭湖区位于长江中游荆江段以南,地跨湘,鄂两省,总面积18700平方公里,其中在湖南省内面积15200平方公里。洞庭湖为我国第二大淡水湖,现有天然湖面约2700平方公里,分为东洞庭湖(1478平方公里)、南洞庭湖(917平方公里)和目平湖(307平方公里)三大片(图1)。洞庭湖区是我国重要的商品粮生产基地和淡水渔业基地,洞庭湖是荆江洪水的天然调节器。研究洞庭湖区、特别是湖泊本身的地貌与环境变迁过程,对于了解洞庭湖的发展演变历史和近期淤积变化,预测今后发展趋势,具有重更多还原

【Abstract】 According to typical drilling sections and other geomorphologic data, the structural features of landforms and the historical changes of the Dongting Lake area are analysed, especially the changes of depositional environment in Quaternary period. The unfavourable consequences caused by the rapid retrogressive evolution of the lake are discussed, such as decline of the lake’s capacity for regulation and storage of floodwater, increase of serious waterlogging and soak, exhaustion of aquatic resources, spread of schistosomiasis and pollution of various water bodies.更多还原