莱州湾沿海带浅层地下咸（卤）水的成因研究

发布时间：2019-04-11 14:30

【摘要】：莱州湾南岸沿海地区的地下淡水是非常宝贵的水资源,近二十年来快速城市化,地下水咸化问题日趋突出。过去三十年的研究主要集中在淡水和海水或卤水之间的混合。本研究在莱州湾南岸分别采集了白浪河河水和河口海水、南岸平原不同位置地下水以及南岸卤水生产区卤水样品共计46件。首先运用溶剂(水分子稳定同位素δD和δ~(18)O)和溶质(Cl~-)的变化关系来识别水分子的属性(大气水分子或海水水分子)以及咸化机理(一般分为蒸发、溶解和混合,淡水和海水混合是混合的一种特例)。然后再从主要成分(K~+、Na~+、Ca~(2+)、Mg~(2+)、HCO_3~-、SO_4~(2-))、卤族元素(F~-、Cl~-、Br~-、I~-)、微量元素(Li+、Sr~(2+)、Ca~(2+))和piper三线图等对河水、地下水和卤水的盐分来源进行溯源分析,结论如下:(1)莱州湾白浪河5件河水样的同位素值证明河水源自上游的白浪河水库,而河水样的盐分除了大气降水输入以外,主要来自蒸发盐溶解,其蒸发盐主要是由卤水晒盐场的盐屑经风力搬运进入河道的。白浪河河口外7件海水样相当白浪河河水和标准海水(未稀释海水)的混合,因受不同季节河水的影响,近岸海水化学组成随时间和空间而变化。(2)莱州湾南岸莱州6件地下水样为稳定同位素参考标准。龙口10件地下水样证明为大气降水直接入渗补给,Cl~-含量源自溶解蒸发盐,主要为石盐晶体(加工石盐)。寿光9件地下水样系南部山区降水经河道输入古巨淀湖入渗补给,盐源主要来自海侵地层盐分溶解和土壤层成岩矿物水解。(3)莱州湾南岸9件卤水样Cl~-含量为58100~101000 mg/L,根据同位素盐效应,对δD和δ~(18)O测定值进行了校正。应用5种地球化学方法对卤水化学组成进行成因分析得出,卤水水分子为大气水成因,排除海水蒸发的余留水,盐度增大与溶解蒸发盐有关,确定蒸发盐的主要盐源来自海洋盐分。综上研究,水化学成分的盐源研究避免不了权重大的来源掩饰权重小的部分。1)河水局限在水库和河道,其化学成分形成主要通过大气降水输入(包括大气气体和海洋气溶胶),还有当地晒盐场盐屑的风力吹扬。这两项盐源来自空中,也是区域性的影响因子。2)海岸带地下水盐分来源主要是海侵地层盐分溶解和土壤带成岩矿物的水解作用。这里往往掩饰掉大气降水和当地晒盐场的盐屑两项空中来源。3)海岸带卤水盐分来源只是反映出海洋盐分,掩饰掉了其它盐源。所以本项研究从河水—地下水—卤水三个部分逐层分析并剥离,三部分盐源加在一起构成区域性盐源影响因子,其中晒盐场盐屑吹扬是造成近期浅层地下水盐度波动的一个重要因素。
[Abstract]:The groundwater in the coastal area of the south coast of Laizhou Bay is a very valuable water resource. In the past two decades, the problem of salinization of groundwater has become more and more prominent because of the rapid urbanization. Research over the past three decades has focused on the mixing of fresh water and seawater or brine. In this study, 46 samples were collected in the south bank of Laizhou Bay, including Bailanghe River and Estuary seawater, groundwater at different locations in the southern bank plain and brine production area in the south bank of Laizhou Bay. First, the solvent (stable isotopes 未 D, 未 ~ (18) O) and solute (Cl~-) of water molecules are used to identify the properties of water molecules (atmospheric water molecules or seawater water molecules) and salinization mechanisms (generally including evaporation, dissolution and mixing). The mixing of fresh water and seawater is a special case of mixing. And then from the main components (K ~, Na~, Ca~ (2), Mg~ (2), HCO_3~-,SO_4~ (2 -), halogen elements (F, Cl, Br, I ~ -), the trace elements (Li, Sr~ (2), Ca~ (2) and piper are used to analyze the source of salt in river water, groundwater and brine. The results are as follows: (1) the isotope values of five samples of Bailang River in Laizhou Bay prove that the river originated from the upper Bailanghe reservoir. In addition to the input of atmospheric precipitation, the salt in the sample of river water mainly comes from the dissolution of evaporative salt, and the evaporative salt is mainly transported into the river by wind from the salt debris from the salt field of brine suntanning field. The seven sea water samples outside the mouth of the Bailang River are a mixture of the Bailang River and the standard sea water (undiluted seawater) due to the influence of the rivers of different seasons. The chemical composition of coastal seawater varies with time and space. (2) six underground water samples from Laizhou Bay, south of Laizhou Bay, are the reference standard for stable isotopes. 10 underground water samples in Longkou have been proved to be direct infiltration replenishment of atmospheric precipitation. The content of Cl~- is derived from dissolved evaporative salt, mainly stone salt crystal (processed stone salt). Nine groundwater samples from Shouguang were fed into paleo-Judian Lake by river channel. Salt sources were mainly from salt dissolution of transgressive strata and hydrolysis of diagenetic minerals in soil layer. (3) Cl~- content of 9 halogen samples on the south bank of Laizhou Bay was 58100 脳 101000 mg/L,. The determination values of 未 D and 未 ~ (18) O have been corrected according to the isotopic salt effect. Five geochemical methods are used to analyze the chemical composition of brine. The results show that the brine molecule is the origin of atmospheric water, and the increase of salinity is related to the dissolution of evaporative salt, and that the residual water of seawater evaporation is excluded. It is determined that the main salt source of evaporative salt comes from marine salt. On the whole, the salt source study of water chemical composition can not avoid the important source hiding the small weight part. 1) the river water is confined to the reservoir and the river course. Its chemical composition is mainly generated by atmospheric precipitation inputs (including atmospheric gases and marine aerosols), as well as wind blowing of salt debris from local salt farms. 2) the source of salt in coastal zone is mainly salt dissolution in transgressive strata and hydrolysis of diagenetic minerals in soil zone. 2) the source of salt in the coastal zone is mainly the dissolution of salt in transgressive strata and the hydrolysis of diagenetic minerals in the soil zone. The source of brine salt in the coastal zone only reflects the ocean salt and hides the other salt sources. 3) the source of brine salt in the coastal zone only reflects the ocean salt, and the other salt sources are covered up by the source of salt debris from the local salt field. Therefore, this study analyzed and stripped off the three parts of river water, groundwater and brine layer by layer, and the three salt sources were added together to form a regional salt source influence factor. The blowing of salt debris in the salt field is an important factor to cause the salinity fluctuation of shallow groundwater in the near future.
【学位授予单位】：中国地质大学(北京)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P641.11

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