为了研究天津七里海湿地水体及其周边水体的水化学和同位素特征,2015年8月10~12日和12月5~7日采集了湿地内的沼泽水、潮白新河水、永定新河水和周边地下水水样,分析水样的稳定氢、氧同位素和水化学组成。结果表明,无论是在8月采样日还是在12月采样日,沼泽水的电导率都比附近的河水高;河水和沼泽水的水化学类型为Na-Cl,地下水的水化学类型为Na-HCO_3。天津七里海湿地的沼泽水和河水的水化学组成主要受控于蒸发结晶作用和人类活动,而地下水中的离子含量与岩石风化有关。8月采样日和12月采样日,沼泽水和河水的同位素组成富集,存在明显的变化;地下水的同位素组成贫化,年内变化小。潮白新河附近的沼泽水同位素组成与河水接近。沼泽水在8月采样日受到强烈的蒸发作用,其过量氘值小于12月采样日。潮白新河上的水闸对河水的同位素和水化学有直接影响,进而影响湿地水质。此外,在高含盐量的土壤环境下,七里海湿地的沼泽水中Na~+和Cl~-含量增加,可能导致水体盐分积累。 In order to study the hydrochemical and isotopic characteristics of the water body and the surrounding water in the Qilihai wetland, Tianjin, marsh water, Chaobaixin River, Yongding New River and the surrounding areas were collected from August 10 to December 12 and December 5 to 7, Groundwater samples, analysis of water samples of stable hydrogen, oxygen isotopes and water chemistry. The results show that the conductivity of marsh water is higher than that of the nearby river in both sampling day and sampling day in December. The water chemistry type of river water and swamp water is Na-Cl, and the water chemistry type of groundwater is Na- HCO_3. The water chemistry of swamp water and river water in the Qilihai wetland of Tianjin is mainly controlled by evaporation crystallization and human activities, while the groundwater ion content is related to rock weathering. August sampling day and December sampling day, the isotopic composition of marsh water and river water is enriched, with obvious changes. The isotopic composition of groundwater is depleted and the change is small during the year. Marsh water isotope composition near Chaobai Xinhe River is close to river water. Swamp water was strongly evaporated on the sampling day in August with an excess deuterium value of less than December sampling date. The sluice on the Chaobai Xinhe River has a direct impact on the isotopes and water chemistry of the river water, which in turn affects the water quality of the wetland. In addition, Na + and Cl ~ - increased in the marsh water of Qilihai wetland in the high salinity soil environment, which may lead to salt accumulation in the water.