摘要
以无定河流域为研究区,分析地下水和地表水水化学特征,讨论溶质来源及其控制因素,为水质管理提供参考依据.考虑季节效应,在枯水期和汛期分别进行水样采集,综合运用图解法、相关性分析和正向推演模型分析水化学时空演化特征,探讨水化学形成机制并定量不同来源对溶质的贡献率.结果表明,无定河流域水体整体呈弱碱性,主要的阴、阳离子分别为HCO^(-)_(3)和Na^(+),水化学类型多数地区呈现HCO^(-)_(3)·SO_(4)-Na·Ca型.水质自西向东沿河道逐渐变差,超Ⅲ类水集中分布在枯水期支流和汛期下游.阳离子交换作用导致水中Na^(+)和K^(+)浓度增多,不同时期水体的NO^(-)_(3)和HCO^(-)_(3)浓度差异性显著,可能受季节降水淋溶土壤与土地利用类型的影响.蒸发岩风化和硅酸盐岩风化对无定河流域水体溶质贡献较大,枯水期分别为35.0%和46.5%,汛期分别为46.7%和42.3%.
Taking Wuding River as the research object, the study explored the hydrochemical characteristics and discussed the source of solute and control factors of groundwater and surface water in the basin, in order to provide a reference for water quality management. Considering the seasonal differences, water samples were collected during the dry season and the flood season. By comprehensively using graphic methods, correlation analysis, and forward deduction models, we analyzed the temporal and spatial evolution characteristics of water chemistry, explored the formation mechanism of water chemistry, and quantified the contribution rates of different sources to solutes. The results showed that the overall water quality was weakly alkaline in Wuding River basin. HCO^(-)_(3)and Na^(+)were the main anions and cations in the water, respectively, and the main water chemistry type was HCO^(-)_(3)·SO_(4)-Na·Ca. The water quality gradually deteriorated along the river course from west to east, and the sampling points that exceeded the level Ⅲ water were mainly distributed in tributaries during the dry season and downstream during the flood season. The cation exchange effect increased the Na^(+)and K^(+)in the water, and NO^(-)_(3)and HCO^(-)_(3)differed significantly in different seasons, which may be affected by seasonal precipitation leaching soil and land use types. Evaporite weathering and silicate weathering were the main sources of solute contribution in the Wuding River basin, which were 35.0% and 46.5% in the dry season and 46.7% and 42.3% in the flood season, respectively.
作者
李书鉴
韩晓
王文辉
李志
LI Shu-jian;HAN Xiao;WANG Wen-hui;LI Zhi(College of Natural Resources and Environment,Northwest A&F University,Yangling 712100,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2022年第1期220-229,共10页
Environmental Science
基金
国家自然科学基金项目(42071043)。
关键词
无定河
水化学
时空差异
离子来源
控制因素
Wuding River
water chemistry
spatiotemporal variation
ion source
control factors
