Temporal and spatial distribution characteristics and source changes of heavy metals in sediments of East Dongting Lake based on multivariate statistical methods
The heavy metal pollution in Dongting Lake is serious due to the intensive human activities such as mining and heavy metal smelting in the upper reaches,which restricts the sustainable development of the region's society and economy.For the uncertain situation of the heavy metal pollution in Dongting Lakre over the past century,this study selected East Dongting Lake as the research object.The spatial and temporal distributions of seven heavy metals(As,Cd,Cr,Cu,Mn,Pb,and Zn)in sediments were analyzed with the help of 210Pb dating technique,and their source was identified by principal component analysis.The results showed that the East Dongting Lake was contaminated by As,Cd,Pb,Cu and Zn in the past 100 years.In DDTH(the nature reserve),the average content of As was relatively high with the value in the lower layer reaching 184.05 mg·kg-1.Except for the lower layer LJ(wharf),the average content of Mn in all the sites exceeded the background value,which needs more attention.The content of heavy metals showed obvious variation along the vertical direction,and the deposition process can be divided into three stages:before 1937,1937-1978,and 1978-2020.The source identification results showed that heavy metal pollution of sediments in East Dongting Lake was mainly from"mining sources"in the early period.In the middle period,it was mainly affected by the"industrial source","agricultural source"and"transportation source".In recent years,the"mixed source"formed the combined domination of the pollution sources.Our findings clarified the spatial distributions of heavy metals in lake sediments and their evolutionary processes of pollution history,and further provided theoretical support for lake environmental management.
heavy metalsEast Dongting Lakesedimentspollution historysources
NETL
NSTL
万方数据
