三门峡库区湿地水化学特征及影响因素分析

Water Chemistry Characteristics and Main Influencing Factors of the Wetland in Sanmenxia Reservoir Area

研究湿地水化学特征对湿地生态保护和高质量发展具有重要意义,以三门峡库区湿地为典型研究区域,采用2018—2019年三门峡水库蓄泄期间4次采样数据,结合三角图、Gibbs图等水化学方法分析了三门峡库区湿地水化学特征及其影响因素,结果表明:三门峡库区湿地水体呈弱碱性,蓄泄期间pH值从潼关到三门峡大坝变化较小,在天鹅湖湿地处出现最大差值,表现为天鹅湖湿地对水体的净化作用;不同时期TDS沿程呈减小趋势,泄水期天鹅湖湿地稀释作用明显;蓄水期溶解氧、电导率、氧化还原电位均高于泄水期的;离子浓度随大坝蓄泄期水位变化而变化,蓄水期离子浓度高于泄水期的,主要阳离子为Na^(+),阴离子为HCO_(3)-,水化学类型为HCO_(3)-SO_(4)-Na-Ca型;三门峡库区湿地水化学特征受硅酸盐岩风化作用和蒸发盐岩溶解影响,此外蓄水期城市生活废污水排放对库区湿地水化学有较显著影响。

It is of great significance to study the characteristics of wetland water chemistry for the ecological protection and high quality development of wetland.Taking the Wetland of Sanmenxia Reservoir as a typical research area,using the sampling data of 4 times during the impoundment period and drainage period of Sanmenxia Reservoir from 2018 to 2019,the hydrochemical characteristics of the wetland of Sanmenxia Reservoir were analyzed by using hydrochemical methods such as triangle plots and Gibbs plots.The results show that the water in the wetland of Sanmenxia Reservoir is weakly alkaline,and the pH value changes little from Tongguan to Sanmenxia dam during the storage and drainage period,during the discharge period,which is influenced by Swan Lake wetland.During different periods,it shows a decreasing trend in different periods.The dilution effect of Swan Lake wetland in the drainage period is obvious;the DO,ORP,and EC contents are shown to be higher in the impoundment period than that in the drainage period.The ion concentration changes with the water level in the dam impoundment period.The ion concentration in the impoundment period is higher than that in the drainage period.The main cation is Na+,the anions are mainly HCO_(3) and the water chemical type is HCO_(3)-SO_(4)-Na-Ca.Changes in hydrochemical characteristics of the wetland of Sanmenxia Reservoir are affected by the weathering of silicate rock and the dissolution of evaporative salt rock.In addition,the discharge of the municipal sewage during the impoundment period also has a significant impact on the hydrochemistry of the wetland in the reservoir area.