中文摘要：

在210Pb同位素测年的基础上,通过对乌梁素海沉积物元素含量的分析,研究了沉积物中元素的变化规律,探讨了沉积物中元素变化的影响因素,结果表明沉积物中Ca、Sr、Cu、Mn、P等元素随深度加深含量下降,其余元素含量随深度加深呈增加的趋势。通过对元素富集系数的变化规律进行研究后,发现Ca、Sr、Cu、Mn、P等元素的富集系数与其含量变化趋势基本相同,反映了该组元素主要受沉积通量的影响;Al、K、Be、Ba、Mg等富集系数与其含量的变化趋势具明显差异,与黏土含量变化一致;而Cr、Fe、Ni、V、Co、Pb、Zn等重金属元素可能受到黏土吸附作用影响。最后,应用有序样品聚类分析方法,对元素这一环境代用指标在研究湖泊历史演化中的作用进行了探讨,研究表明：在湖泊演化过程中,湖泊的形成、20世纪70年代入湖水量的急剧改变以及近年来河套灌区化肥用量逐年加大、大量生活污水和工业废水排入等人类活动的增强等事件,均在湖泊沉积物元素的变化中有所体现。

英文摘要：

On the basis of 210Pb dating,the variation of elemens was studied for the Ulansuhai Lake sediments.Using the cluster analysis method,the influence factors were also discussed.The results show that some elements,such as Ca,Sr,Cu,Mn,P and so on,declined with depth generally,but the remaining ones had an overall upward increasing trend.By the analysis of enrichment coefficient variations of the lake sediment elements,it was found that the enrichment coefficient of some elements,for example,Ca,Sr,Cu,Mn and P,have the same trend with their contents,suggesting that they was affected by the sediment input.The others,such as Al,K,Be,Ba,Mg,have different trend with their element contents,but were in line with the clay content.Heavy metals,such as Cr,Fe,Ni,V,Co,Pb,Zn,may be affected by clay adsorption.Finally,the ordered specimen cluster analysis method was applied to study the lake environmental changes.It was found that the distribution of sediment elements shows some kinds of environmental events in the process of lake evolution,such as the lake formation,the abrupt change in water quality in 1970s and the discharge of domestic sewage and industrial wastewater into the lake in recent years and so on.