针对天津滨海平原水库普遍存在的水质咸化问题，以北大港水库为研究对象，采用野外调查和取样分析方法，识别了北大港水库不同季节水质咸化垂直分布规律，同时分析了水库水质咸化机理及其影响因素。研究结果表明：从电导率、氯离子和总溶解性固体（TDS）等代表性咸化指标来看，相对于引黄水，水库水各站点均存在咸化现象，并且出库口水质咸化程度明显高于进水口；不同站点电导率、氯离子浓度和总溶解性固体（TDS）值分别为867.5μs/cm、0.41g/L和1.46g/L，水体呈弱碱性；北大港水库水质咸化程度有季节性变化，为夏季略高于春季；水库各站点氯离子浓度和TDS值垂向上均随深度的增加而降低，但不明显；而电导率则随着深度的增加而增加，且变化明显。研究还发现，水库水质咸化受土壤含盐量、温度和混合作用的影响：从各站点水平分布来看，越靠近海岸线土壤含盐量越高，水质咸化现象越严重；温度的升高会影响底泥盐分的释放，温度越高，底泥中Cl-越容易释放；引黄水进入水库后，水库水体垂向发生了混合作用，导致氯离子和TDS垂向方向变化很小。

Aims at the problem of water sanilization widespread existed in Tianjin coastal reservoirs,the field investigation and sampling analysis method were conducted to vertical distribution of salinization in various seasons for Beidagang reservoir. Water salinization mechanism of reservoir and its impact factors were analyzed. Results show that from to the each site's representative sanilization index, such as electric conductivity, chloride ion and total dissolved solid (TDS),relative to the water diverted from the Yellow River, the sanilization tendency was presented for each site of reservoir, and the water sanilization phenomenon of outer was obviously higher than that of entrance. In different sites of the reservoir, the average level of electric conductivity, chlorine ion and TDS of reservoir water was 867.5μs/cm,0.41 g/L and 1.46 g/L respectively. It was weak alkaline in different sites of reservoirs. Seasonal variation characteristics of salinization indicators, such as Electric conductivity, chloride ion and TDS of Beidagang reservoir were showed that in winter was slightly higher than in spring. Vertical variation characteristics of the reservoir water of chloride ion and TDS vertical changed not significantly, and presented that chloride ion and TDS decreases with the increase of depth, but presented the opposite rule for electric conductivity. The study found that the sanilization of reservoir water quality was influence by soil salinity, temperature and the mixing actions.The closer to the coastline, and the higher soil salt content was, and the more serious sanilization phenomenon of water quality was from to the sites' horizontal distribution of sanilization index. Temperature rising would affect the release of salt from the sediment, and the higher the temperature was, the easier release for the chlorine ion of sediment was. Vertical mixing action were happened, and leading to little vertical direction change of chloride ion and TDS.

天津市自然科学基金重点项目(11JCZDJC24700)；国家自然科学基金项目(40872156)