Impacts of ecological water replenishment on the hydrochemical characteristics of surface water and groundwater in Lake Baiyangdian Watershed

生态补水是维持和改善白洋淀生态环境的重要途径.为研究生态补水对白洋淀水环境的影响，分别在补水前与补水后采集淀水、河水及地下水样品，分析区域地表水和地下水水化学特征.结果表明：（1）白洋淀补水前、后地表水与地下水的水化学组成中Na+为主要阳离子，补水后阴离子以HCO3-为主，淀区南部地表水电导率高；补水后地表水与地下水Ca2+、Mg2+和HCO3-浓度显著增加，水体电导率降低.（2）补水前地下水为Na-HCO3型水，地表水主要为Na-Cl·SO4及Na-Cl·HCO3类型；补水后地表水与浅层地下水向Ca·Mg-HCO3型演化，深层地下水水化学类型基本保持不变.（3）生态补水使白洋淀水位升高，淀区水面积增大，缓解了水资源短缺的问题；同时也使浅层地下水水化学组成发生改变，而深层地下水暂未受到影响.生态补水后，受稀释和混合作用的影响，水体Na+、Cl-和SO42-浓度显著下降，Ca2+、Mg2+及HCO3-浓度增加.在白洋淀生态补水中应先治污，后补水，以减少补水过程中污染物向淀区的运移，还应注意区域地下水位上升过程中的阳离子交换及水岩相互作用，为合理调配生态补水及改善白洋淀生态环境提供科学依据.;Ecological water replenishment is an important way to maintain and improve the ecological environment of Lake Baiyangdian Watershed. In order study impact on Watershed, samples lake water, river groundwater were collected before after respectively, hydrochemical characteristics surface analyzed. The results showed that:(1) Before replenishment, sodium-ion was main cation in composition groundwater; bicarbonate radical-ion anion conductivity south high. After mass concentrations calcium-ion, magnesium-ion increased significantly, decreased. (2) Na-HCO3 type, mainly Na-Cl·SO4 Na-Cl·HCO3 types; shallow evolved into Ca·Mg-HCO3 types deep basically unchanged. (3) Ecological level area Baiyangdian, alleviating problem shortage; meanwhile, changed, while not affected. sodium-ion, chloridion-ion sulfate-ion decreased increased. addition, exchange rock interaction rising process regional should be paid attention to, so as provide scientific basis for rational allocation improvement watershed.