基于多重水质评价的干旱区灌溉对区域地下水水质的影响

通过分析河套灌区义长灌域内32口地下水监测井水质数据，依据地下水质量标准(GB/T 14848—2017)，采用内梅罗指数法、改进内梅罗指数法、模糊数学综合评判法和单因子评价法等多重水质评价方法，对灌溉前后区域地下水水质进行了评价，并对比和评估了不同地下水水质评价方法的有效性. 评价结果显示，采用模糊数学综合评判法评价时，灌溉前地下水各水质所占比例分别为V类（81.25%）、IV类（6.25%）、III类（9.38%）、II类（3.12%），灌溉后为V（84.38%）、IV（6.25%）、III（9.38%）. 这一结果与单因子评价法的评价结果最为接近，契合度高达85.9%，具有显著的合理性. 在此基础上，通过灌溉前后水质变化因素分析，发现引起水质恶化的指标主要为氯化物、氨氮、硫酸盐和总溶解固体等. 评价结果可为灌区地下水环境保护和可持续开发利用提供一定的参考. 

Impact of irrigation on regional groundwater quality in arid area - an multiple water quality assessment

Observed data at 32 monitoring wells in Yichang Irrigation Sub-district of Hetao Irrigation District and Groundwater Quality Standards (GB/T 14848—2017) were used to evaluate regional groundwater quality before and after irrigation with multiple water quality assessment methods including Nemerow Index, improved-Nemerow Index, fuzzy comprehensive evaluation method and Single-factor assessment. Effectiveness of different comprehensive assessment methods was evaluated. Fuzzy comprehensive evaluation was found to be more effective and more objective, consistency between this evaluation method and Single-factor method was 85.9%, fuzzy comprehensive evaluation can therefore be used to evaluate regional groundwater quality, particularly in arid areas. Fuzzy comprehensive evaluation classified the groundwater quality in five grades. The percent before irrigation was V 81.25%, IV 6.25%, III 9.38%, II 3.12%; after irrigation V 84.38%, IV 6.25%, III 9.38%. Analysis of groundwater quality indicators before and after irrigation identified predominant impacting factors: chloride, ammonia nitrogen, sulfate and total dissolved solids (TDS). These findings will be useful for the protection and sustainable utilization of regional groundwater in Hetao Irrigation District.