基于电导率和结构稳定性阳离子比的微咸水灌溉水质评估方法  

Water quality assessment method based on the electrical conductivity and cation ratio of soil structural stability under saline water irrigation

作　　者：张体彬 闫思慧[1,2] 罗敏 王春 张通港 程煜 冯浩 Zhang Tibin;Yan Sihui;Luo Min;Wang Chun;Zhang Tonggang;Cheng Yu;Feng Hao(Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas,Ministry of Education,Northwest A&F University,Yangling 712100,China;College of Water Resource and Architectural Engineering,Northwest A&F University,Yangling 712100,China;Institute of Water and Soil Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,China)

机构地区：[1]西北农林科技大学旱区农业水土工程教育部重点实验室,杨凌712100 [2]西北农林科技大学水利与建筑工程学院,杨凌712100 [3]中国科学院水利部水土保持研究所,杨凌712100

出　　处：《农业工程学报》2022年第20期105-112,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目(2021YFD1900700);陕西省创新能力支撑计划项目(2022PT-23)。

摘　　要：电导率(Electrical Conductivity,EC)和结构稳定性阳离子比(Cation Ratio of Soil Structural Stability,CROSS)是评估微咸水对土壤渗透性能影响的重要指标。虽然CROSS全面地考虑了Na^(+)、K^(+)、Ca^(2+)和Mg^(2+)对土壤结构稳定性的复杂影响,但CROSS的离子浓度系数在不同地区的适用性存在差异,有必要根据当地的水质条件确定基于EC和CROSS评估方法的分类标准。该研究旨在分析CROSS替代钠吸附比(Sodium Adsorption Ratio,SAR)评估水质危害的合理性以及其在河套灌区的适用性。在河套灌区不同区域采集73份地下水水样,并采用EC和SAR、EC和CROSS对其进行评估。结果表明,基于2种方法的地下水分类结果中,仅有34.25%的水样分类结果相同,并且不同的CROSS计算方法(基于阳离子相对絮凝能力(Flocculation)的CROSS_(f)、相对分散能力(Dispersion)的CROSS_(d)和优化的(Optimal)CROSS_(opt))在河套灌区的适用性也不相同。建议采用CROSS_(d)或CROSS_(opt),并结合土壤盐分和离子浓度评估河套灌区地下水水质。该评估方法更全面地考虑了地下水和土壤中的离子组成对土壤渗透性能的影响,有效避免了不合理的微咸水利用导致的土壤结构恶化等问题,可为微咸水的安全可持续利用提供理论支撑。The Electrical Conductivity(EC)and cation concentration in the soil solution are important indicators to assess the stability of soil structure.Previously,Sodium Adsorption Ratio(SAR)is used to quantify the impact of soil alkalinity and Na^(+)concentration on the soil structural stability.However,the SAR water quality assessment cannot fully meet the soil structure in the areas with high concentrations of K^(+)and Mg^(2+).The reason is that the SAR is focused only on the dispersion of Na+on the soil particles and the similar promotion of Ca2+and Mg2+on the soil flocculation.Fortunately,a new assessment index of water quality called as Cation Ratio Of Soil Structural Stability(CROSS)can comprehensively consider the complex effects of Na^(+),K^(+),Ca^(2+),and Mg^(2+)on the soil infiltration,in order to quantify the extent of different cations on the soil dispersion or flocculation.Much effort was made to quantify the Na^(+),K^(+),Ca^(2+),and Mg^(2+)on the stability of soil structure,the relative dispersion power of K^(+)versus Na^(+),and the relative flocculation power of Mg^(2+)versus Ca^(2+).Among them,the concentration coefficients were adjusted to constantly modify the CROSS equation.The CROSS can be expected to serve as the surrogate index of SAR for the assessment of water quality,due to the high accuracy of the coefficients to compensate for the SAR without considering K^(+)effects.This study aims to(1)analyze the influence of K^(+)and Mg^(2+)on the soil structure,in order to develop the SAR alternative technology(CROSS)for the water quality assessment.Although the effect of K^(+)on the soil dispersion was not as capable as that of Na^(+),the irrigation water with a high concentration of K^(+)reduced the soil-saturated water conductivity,to remove the large soil pores for better dispersion of soil particles.The dispersion effect of Mg^(2+)on the soil was more capable than that of Ca^(2+).But,the accumulation of Mg^(2+)in soil caused the risk of soil salinization;(2)evaluate 73 water samples collected from th

关 键 词：入渗 水质 评估 SAR CROSS 微咸水 阳离子 

分 类 号：S152.7[农业科学—土壤学]