白洋淀流域典型河流水化学季节性变化控制机理  

Mechanisms controlling seasonal variations of hydrochemistry in a typical river of the Baiyangdian Basin

作　　者：杨曦[1] 蒋小伟[1] 耿晓虹 马荣涛 姬韬韬 张志远 YANG Xi;JIANG Xiaowei;GENG Xiaohong;MA Rongtao;JI Taotao;ZHANG Zhiyuan(Key Laboratory of Groundwater Conservation of Ministry of Water Resources,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]中国地质大学(北京)水利部地下水保护重点实验室,北京100083

出　　处：《水文地质工程地质》2024年第6期25-35,共11页Hydrogeology & Engineering Geology

基　　金：科技部科技创新专项(2022XACX0900)。

摘　　要：为查明白洋淀入淀河流水化学组分的季节性变化特征及控制机理,选择白洋淀流域的安格庄水库—中易水河—南拒马河—白沟引河为研究对象,对比2023年雨季前、雨季和雨季后的河流水化学组成,利用描述性统计、Piper三线图、Gibbs图、端元图以及PHREEQC模拟等方法进行分析。结果表明:上游安格庄水库水化学组分在2023年具有明显的季节性变化特征,在很大程度上控制了下游河流水化学组成;易水河与南拒马河交汇后水化学组分与易水河更接近,指示易水河流量占优并控制了两者混合后的南拒马河水化学组分;易水河—南拒马河在雨季前、雨季后因流量小、风化作用弱表现出主要离子随径流距离无明显变化,而在雨季水库大流量放水期间,河道内碳酸盐岩矿物的强烈风化导致主要离子浓度随径流距离急剧增大。端元分析和PHREEQC模拟结果表明雨季河水主要发生的水文地球化学过程为方解石、石膏、石盐和白云石的溶解/风化。作为直接汇入白洋淀的河流,白沟引河在雨季前的水化学组分受蒸发浓缩作用控制,而在雨季和雨季后的水化学组分受南拒马河与白沟河混合作用控制。该研究加深了对河流水化学组分控制机理的认识,有助于分析白洋淀的水化学季节性变化特征。To investigate the seasonal variation characteristics and controlling mechanism of the hydrochemistry of rivers that flow into the Baiyangdian Basin,the Angezhuang Reservoir—Zhongyishui River—Nanjuma River—Baigou Canal was selected to compare the hydrochemical composition of the rivers pre and post-rainy season in 2023.Various methods,including mathematical statistics,Piper diagrams,Gibbs diagrams,end-member analysis,and PHREEQC simulation,were employed.The results indicate that the hydrochemical characteristic of the Angezhuang Reservoir exhibited seasonal variation in the year 2023,which significantly influenced the hydrochemistry of the downstream river.At the confluence of the Yishui River and the Nanjuma River,the hydrochemical components were predominantly similar to those of the Yishui River,indicating that the Yishui River's flow primarily governs the mixed hydrochemistry composition of the Nanjuma River.Before and after the rainy season,due to low flow rates and weak weathering,the primary ions in the Yishui-Nanjuma River showed minimal changes with the runoff distance.During the rainy season,however,the large discharge flow from the reservoir and intense rock weathering resulted in a sharp increase in the concentration of major ions with the runoff distance.End-member analysis and PHREEQC simulation results indicated that the main hydrogeochemical processes occurring in river water during the rainy season were the dissolution/weathering of calcite,gypsum,halite,and dolomite.As a river that directly flows into Baiyangdian Basin,the hydrochemical composition of the Baigou Canal was influenced by evaporation and concentration before the rainy season,while during and after the rainy season,it was controlled by the mixing of the Nanjuma River and Baigou River.This study enhances the understanding of the mechanisms controlling river hydrochemical composition and aids in analyzing the origins of Baiyangdian Lake’s water quality.

关 键 词：白洋淀流域 地表水 水化学 季节变化 化学风化 

分 类 号：P641.3[天文地球—地质矿产勘探]