巢湖富营养化过程的沉积记录

Sedimentary Records of Eutrophication for the Last 100 Years in Caohu Lake

土地利用和人类活动加剧所导致的营养元素输入的增加是引起湖泊富营养化趋势增强的重要原因。巢湖沉积钻孔柱状样中总有机碳和总氮自 2 0世纪 70年代以来呈明显升高趋势 ,分别增加了 2 .5、2 .9倍。由柱状样中的TOC/TN比值、TARHC、OEP判断得出 ,19世纪末到 2 0世纪 4 0年代中期TOC是陆源和内源两种来源并重 ;2 0世纪 4 0年代中期到 2 0世纪 70年代初期以陆源为主 ,并可能存在石油污染 ;2 0世纪 70年代以来沉积物有机质中藻类来源的有机质占主要地位。巢湖沉积柱状样的研究表明 2 0世纪 70年代以来巢湖富营养化开始恶化。

Changes in the delivery of nutrients from land usage and anthropogenic emissions, are known to result in eutrophication in lakes. Both accumulation rates of total organic carbon and total nitrogen concentrations show increasing trends since 1970s, and have increased by as much as 2.5, 2.9 times in Caohu lake sedimentary core. Based on total organic carbon, total nitrogen, the ratios of total organic carbon and total nitrogen , TARHC and OEP, the environmental evolutions have been reconstructed since 1898. From 1898 to 1946 the sedimentary organic matter in Caohu lake was attributed to the mixture of terrestrial plants and aquatic algae. From 1946 to 1972 the source of land plant dominated the organic matter and there may be petroleum pollution. From 1972 to present, the source of algae dominated the organic matter of Caohu lake sediment. It can be concluded that sediment organic matter recorded the beginning of eutrophication at Caohu lake since 1970s.