| 河套灌区地下水化学演变特征及形成机制 |
| 摘要点击 2334 全文点击 824 投稿时间：2020-03-13 修订日期：2020-04-02 |
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| 中文关键词 河套灌区 地下水 水化学特征 盐化作用 形成机制 |
| 英文关键词 Hetao irrigation area groundwater hydrochemical characteristics salinization formation mechanism |
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| 中文摘要 |
| 地下水资源是我国西北干旱区的重要资源，但不合理的开发利用导致系列生态环境问题，深入探究地下水化学演变特征及形成机制，对于地下水资源的合理利用具有重要意义.以河套灌区永济灌域为研究区，综合运用聚类分析和因子分析等统计学方法，研究了该区域地下水化学演化特征并阐明了地下水化学的形成机制，说明不同因子的影响程度.结果表明，研究区地下水阳离子以Na++K+为主，阴离子分别以Cl-和HCO3-为主，且Na++K+和Cl-离子具有较高的空间变异性，是决定地下水盐化的主要因子，地下水化学类型以Cl-Na、HCO3 ·Cl ·SO4-Na和HCO3-Na型为主；通过聚类分析，研究区地下水可分为4类（A1、A2和B1、B2类），其中A1类地下水为高矿化度Cl-Na型水，A2、B1和B2类地下水主要为HCO3 ·Cl ·SO4-Na和HCO3-Na型水，结合因子分析，该区域地下水化学主要受"盐化"作用、碳酸盐岩溶解作用和人类活动影响，影响程度分别占了45.976%、23.853%和16.678%.蒸发盐岩溶解和阳离子交换作用是研究区Na+和Cl-积聚的重要来源，农业灌溉（对土壤盐分的淋洗）和干旱（蒸腾蒸发强烈）是地下水盐化的关键驱动因素. |
| 英文摘要 |
| Groundwater resources are important sources of water in the arid region of northwestern China, but their overexploitation and utilization has led to a series of ecological and environmental problems. Exploring the characteristics and mechanism of groundwater chemical evolution is important for the rational use of groundwater resources. The characteristics of groundwater chemical evolution were studied in the Yongji Irrigation Area of Hetao Irrigation District and the formation mechanism of the chemical compounds in groundwater were investigated using cluster analysis, factor analysis, and other statistical methods. The influence degree of different factors was calculated. The results showed that the major cations in groundwater in the study area were Na+ and K+, and the major anions were Cl- and HCO3-. Moreover, Na+, K+, and Cl- showed high spatial variability and were the main factors contributing to groundwater salinization. The major chemical compounds in the groundwater in the study area were Cl-Na, HCO3 ·Cl ·SO4-Na, and HCO3-Na. Based on the cluster analysis results, the groundwater was divided into four categories (A1, A2, B1, and B2), of which A1 was highly mineralized by Cl-Na type water, while A2, B1, and B2 were mainly HCO3 ·Cl ·SO4-Na and HCO3-Na type water. Principal component analysis results suggest that groundwater chemistry was mainly affected by salinization, carbonate karstification, and human activities with the influence degrees of 45.976%, 23.853% and 16.678%, respectively. Evaporation, salt rock dissolution, and cation exchange were important sources of Na+ and Cl- accumulation in the irrigation area. Agricultural irrigation (leaching of soil salts) and drought (intense transpiration) were the key drivers of groundwater salinization in the irrigation area. |
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