水位波动下的呼伦湖上覆水体与沉积物间隙水之间溶质的运移特征

发布时间：2019-08-17 19:33

【摘要】：为了探求内蒙古呼伦湖上覆水体和沉积物间隙水之间溶质运移机制,对呼伦湖的1个沉积物柱芯的间隙水、3个湖泊水体以及湖周边7个地下水体中的氯离子(Cl~-),氢、氧稳定同位素(δD和δ~(18)O)分别进行分析测试,并利用其示踪性对沉积物中溶质运移特征进行研究.结果显示,δD、δ~(18)O和Cl~-浓度在不同水体中的分布具有相似的分布规律,整体上从底部沉积物到上部湖水浓度分布呈现逐渐递减的抛物线趋势,在间隙水中最大值位于所取沉积物柱芯的最深处,Cl~-浓度为306 mg/L,δD和δ~(18)O分别为-58‰和-5.9‰;最小值位于沉积物柱芯上层,并与上覆水体中的值相似,Cl~-浓度为159 mg/L,δD和δ~(18)O分别为-66‰和-7.3‰.为了明确沉积物柱芯中间隙水的高浓度Cl~-和偏正δD、δ~(18)O的来源,比较不同水体的δ~(18)O-δD关系点分布,表明含有偏正值的δD、δ~(18)O和高浓度Cl~-的间隙水与上覆湖水关系密切,可能是由于低水位时期湖水与间隙水相互发生扩散作用而产生的结果.一维对流扩散迁移模型证实扩散作用是控制着沉积物间隙水中溶质浓度在垂向上分布的主要机制,同时湖水水位的变化会影响沉积物间隙水与上覆水体的扩散过程,特别是在水位上升期,富集在沉积物中的溶质可能成为湖水的重要物质来源,影响上覆水体的水质.因此,对于封闭湖泊水位的控制和管理不仅在维持湖泊水量方面有着直接的作用,同时在稳定湖泊水质条件上也有着重要的意义.
[Abstract]:In order to explore the mechanism of solute transport between overlying water body and sediment gap water in Hulun Lake, chlorine ion (Cl~-), hydrogen and oxygen stable isotopes (未 D and 未 ~ (18) O) in one sediment column core, three lake waters and seven groundwater bodies around the lake were analyzed and tested, respectively, and the solute transport characteristics in sediments were studied by using their traceability. The results show that the distribution of 未 D, 未 ~ (18) O and Cl~- concentrations in different water bodies is similar, and the distribution of 未 D, 未 ~ (18) O and 未 ~ (18) O concentrations from the bottom sediment to the upper lake water shows a parabola trend. The maximum value in the gap water is located in the deepest part of the sediment column core, and the Cl~- concentrations are-58 per thousand and-5.9 per thousand, respectively. The minimum value is located in the upper layer of sediment column core and is similar to that in overlying water. Cl~- concentrations of 159 mg/L, 未 D and 未 ~ (18) O are-66 per thousand and-7.3 per thousand, respectively. In order to clarify the source of high concentration Cl~- and bias 未 D, 未 18 O in the middle gap water of sediment column core, the distribution of 未 18 O 未 D relation points in different water bodies is compared. it is shown that the gap water containing bias value 未 18 O and high concentration Cl~- is closely related to overlying lake water, which may be due to the diffusion of lake water and gap water at low water level. The one-dimensional convective diffusion migration model proves that diffusion is the main mechanism to control the vertical distribution of solute concentration in sediment gap water. At the same time, the change of lake water level will affect the diffusion process of sediment gap water and overlying water body, especially during the rising period of water level, the solute enriched in sediment may become an important material source of lake water and affect the water quality of overlying water body. Therefore, the control and management of closed lake water level not only plays a direct role in maintaining lake water quantity, but also plays an important role in stabilizing lake water quality conditions.
【作者单位】：内蒙古农业大学水利与土木建筑工程学院;
【基金】：国家自然科学基金项目(51669022,51509133) 高等学校博士学科点专项科研基金项目(20131515120005) 国家留学基金委项目(201408150013)联合资助
【分类号】：X524

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