贵州乌江水系的水文地球化学研究

HYDROGEOCHEMISTRY OF WUJIANG RIVER WATER IN GUIZHOU PROVINCE

乌江水系河流的水化学组成代表了典型碳酸盐岩地区河流的相应化学组成 ,显示了与世界主要河流不同的水文化学特征 :河水含有较高的溶质浓度 ,河水水化学组成以 Ca2 +和 HCO3 -为主 ,其次为 Mg2 +和 SO4 2 -,Na+ +K+和 Cl-+Si分别只占阳离子和阴离子组成的 5%～10 %。这表明乌江流域河水中水化学组成主要来源于碳酸盐风化 ,硅酸盐、蒸发盐风化对水中溶质的贡献很小 ,农业活动、开矿和工业污染对水体化学组成有一定影响。

The chemical composition of Wujiang River water represents that of the river water from the typical carbonate rock areas.Its hydrogeochemical characteristics are different from those of the global major rivers:the river and its tributaries have high total dissolved solid concentrations, with Ca 2+ and HCO 3 - being dominant, Mg 2+ and SO 4 2- coming next. Both Na ++K +and Cl -+Si account for 5%~10% of the cations and anions,respectively. These general features show that the chemical composition of the river water is mainly controlled by carbonate rock weathering,and the silicate and evaporate weathering plays a less important role in its formation. Production activity, mining practice and industry pollution have a certain influence on the chemical composition of the river water.