城市化过程对北京周边河流水化学特征的影响

The Influence of Urbanization on Water Chemistry in Rivers Near Beijing

城市河流既是人们赖以生产、生活的重要资源,也具有承担各种社会活动废物排放的特殊功能,对城市河流水化学时空变化及离子组分的研究对比,能够揭示城市化对河流的影响.本文通过采集潮白河、北运河北京段及其上游温榆河河水、及周边地区地下水和降水样品,进行水中主要离子分析,并结合1980-2006年温榆河水化学资料探讨城市化过程对河水主要离子的影响.结果显示,岩石风化仍是控制河水中主要离子成分的主导因素,潮白河水系表现出受硅酸盐岩风化影响,温榆河、北运河与潮白河相比,有明显的受人类活动干扰的特征.随着城市化进程的加剧,人类生活与工业活动对河水的干扰越来越显著,以Cl-、NO 2-、K+、Na+、Ca2+和SO24-较明显,地区间大气降水的差异也造成了河水离子组分的不同.

River flowing through urban is not only the vital resource on which human lives on,but also a receivier of diverse discharges from social activities.Rearch on water chemistry and major ion source of river near urban area can reveal the influence of urbanization on water.By collecting the river water samples in Chaobaihe River,Beiyunhe River and Wenyuhe River,groundwater and precipitation samples in the water system,combined with the water chemistry records of Wenyuhe during 1980 and 2006,major ion analysis is conducted.The result shows that pH,the concentration of NO 3-and Mg2 ＋ keep decreasing while the concentration of Cl-,NO 2-,K ＋,Na ＋,Ca2 ＋,TZ ＋ and TZ-all increase during the same periods.Although the urbanization procedure and the influence of human activities on water chemistry are more and more obvious,rock weathering is still in the dominant factor of rivier water chemistry.Sillicate weathering impact can be seen in Chaobaihe River while Beiyunhe and Wenyuhe appears to be influenced by anthropogenic factor.In addition,differences in precipitation also cause the variation of major ions in water.