选择天津滨海地区北大港水库为研究对象，采用野外调查和数据分析相结合的方法，于夏季对水库不同位 置取样，分析水体 pH 值和主要咸化指标溶解性总固体（TDS）及 Cl ?质量浓度，研究北大港水库不同位置水质咸化 的变化规律，对水库咸化机理进行探讨。研究发现：沿着水流方向自西向东，TDS 和 Cl ?质量浓度呈现“水库上游 闸＞水库下游闸”的分布特征，而 pH 值正好相反，沿着水流方向水体咸化呈现逐渐减弱的趋势；北大港水库水体 各指标在垂向分布上可分为两种类型：“混合型”水体，多分布在水库水流上游西侧进水闸口（南岸进水闸、赵连 庄闸、马圈进水闸、大港农场闸和刘岗庄闸），水库东南部的沙井子闸以及东北部的出水闸（十号调节闸和排咸 闸）；“分层型”水体，TDS 和 Cl ?质量浓度在垂向上均随着深度的增加而增加，其中三号泄水闸最具代表性。沉积 物盐分释放对水库咸化有影响。

Reservoirs salinization is a common environmental problem in coastal areas. After the salinization of the reservoir, salt will be transferred to the soil, seriously affecting agricultural production. The salinization of reservoir water also has an impact on industrial production. When the salinization of reservoir water cannot meet the industrial water demand, desalting equipment needs to be installed, which increases the cost of enterprises. Thus, it leads to the deterioration of the water quality of the deep fresh water, and even the destruction of the deep groundwater resources, seriously affecting people's daily drinking. Many experts and scholars have carried out relatively comprehensive research on the salinization of coastal reservoirs, but the research on the spatial variation law and salinization mechanism of reservoir salinization is still insufficient. Studying the problem of reservoir salinization can not only save resources and control costs, but also reduce economic losses caused by salinization, improve people's drinking water quality, deepen people's understanding of reservoir salinization, and provide a sufficient theoretical basis for the prevention and control of reservoir salinization. Beidagang Reservoir in Tianjin Binhai area was selected as the research object, and the method of combining field investigation and data analysis was used to sample different locations of the reservoir in summer to analyze the pH of the water body, the content of dissolved total solids (TDS) and Cl? to study the change law of water salinization in different locations to explore the mechanism of reservoir salinization. The study found that along the flow direction from west to east, the concentration of TDS and Cl? presents the distribution characteristics of "upstream gate of the reservoir>downstream gate of the reservoir", while the pH value is the opposite. Along the flow direction, the salinization of the water body shows a gradual weakening trend. The vertical distribution of water body indicators can be divided into two types: "mixed type" and "stratified type". The "mixed" water body is mainly distributed at the intake gate on the west side of the upstream of the reservoir (south bank intake gate, Zhaolianzhuang gate, Maquan intake gate, Dagang Farm gate and Liugangzhuang gate), the Shajingzi gate in the southeast of the reservoir and the outlet gate in the northeast (No. 10 regulating gate and salt drainage gate). The "stratified" water body is mostly distributed in the No. 3 sluice gate. The concentration of TDS and Cl? in the "stratified" water body increases vertically with the increase of depth, and the vertical distribution characteristics of the No. 3 sluice gate are the most obvious. The pH value of sediment presents the distribution trend of "upstream gate of reservoir>downstream gate of reservoir", while the total salt content and Cl? concentration of sediment presents the distribution trend of "downstream gate of reservoir>upstream gate of reservoir". The total salt content and Cl? content of the sediment in upstream of the reservoir are low, and the TDS and Cl? concentrations of the water in upstream of the reservoir are high. However, the total salt content and Cl? content of the sediment in downstream of the reservoir are high, and the concentration of TDS and Cl? in the water in downstream of the reservoir is low, which indicates that the release of sediment salt has an impact on the salinization of the reservoir. Therefore, it is possible to carry out reasonable salt-control operations on the water body at upstream of the reservoir, such as arranging the reasonable water inflow of the inlet gate and the reasonable water outflow of the outlet gate, to further reduce the intensification of water salinization.