白洋淀流域地表水化学特征及控制因素

为探究半干旱区地表水化学特征及物质来源，以白洋淀流域为研究对象，利用Piper三线图和Gibbs水岩模型，对地表水的主要离子组成特征及其来源进行分析。结果表明:白洋淀流域地表水pH为7.56~8.23时，呈弱碱性，且溶解性总固体（TDS，100~650 mg/L）在流域的不同空间区域表现为淀区 > 下游 > 上游。白洋淀流域地表水阳离子以Na+和Ca2+为主，离子总量占比76.60%；阴离子以HCO₃-为主，约占阴离子总量61.52%。地表水的水化学类型为HCO₃-Ca型（上游水体）和HCO₃·SO₄·Cl-Na·Ca型（下游河流和淀区）。白洋淀水文地球化学过程受到人类活动和自然作用的双重控制；自然作用下，白洋淀流域地表水中的离子来源于岩石风化（碳酸盐岩及硅酸盐岩的风化溶解），同时受到蒸发-结晶作用影响。

HYDROCHEMICAL CHARACTERISTICS AND POSSIBLE CONTROLS OF THE SURFACE WATER IN LAKE BAIYANGDIAN BASIN

To explore the characteristics and sources of surface water hydrochemistry in semi-arid areas, we analyzed the main ion composition characteristics and sources of surface water in Lake Baiyangdian basin, using hrochemical technics such as Piper Triangular diagrams and Gibbs water-rock model. The results showed that the pH of the surface water in the Lake Baiyangdian basin varied from 7.56 to 8.23, which was weakly alkaline. And the total dissolved solids, was 100 mg/L to 650 mg/L in different regions of the basin, ranking as Lake Baiyangdian > downstream > dpstream. The cations in the surface water of Lake Baiyangdian basin were mainly Na+ and Ca2+, which accounted for 76.60% of the total cations. And the anions were mainly HCO₃-, which accounted for about 61.52% of total anions. The water chemistry types of surface water were HCO₃-Ca in upstream, and HCO₃·SO₄·Cl-Na·Ca in downstream and Lake Baiyangdian. The hydrogeochemical process of Lake Baiyangdian basin was controlled by both human activities and natural functions. For natural sources, the ions of the surface water of the Lake Baiyangdian basin originated from rock weathering, carbonate weathering and silicate weathering mainly, which also affected by evaporation-crystallization.