泾惠渠灌区地下水水质特征及评价

Characteristics and evaluation of groundwater quality in Jinghui Canal irrigation area

泾惠渠灌区位于关中平原中部,是陕西省粮食主要产区之一,地下水利用超过区域水资源利用总量的50%。为合理开发利用泾惠渠灌区浅层地下水,保障灌区粮食供应,以泾惠渠水和全区均匀分布的47个浅层地下水采样点水质数据为基础,采用模糊综合优化模型、Wilcox、USSL图解法与单因子评价方法对灌区浅层地下水水质进行评价分析。结果表明:①灌区地下水溶解性总固体值较高,阳离子以Na^(+)为主,Ca^(2+)、Mg^(2+)次之,阴离子中主要以SO_(4)^(2-)为主,地下水化学组分主要受溶滤作用和浓缩作用的影响。②泾惠渠灌区浅层地下水水样均为Ⅲ级水,长期灌溉会导致作物减产,农田被破坏;渠水水样为Ⅱ级水,优于地下水,可用于灌溉。③通过Wilcox、USSL图解法与单因子评价方法对模糊综合优化评价结果进行验证,表明模糊综合优化模型适用于研究区地下水水质评价分析且结论较为可靠。研究结果可为泾惠渠灌区地下水环境的治理与预防提供科学依据,对保证灌区粮食安全有着重要意义。

The Jinghui Canal irrigation area is located in the middle of Central Shannxi Plain,which is one of the main grain production areas of Shaanxi Province.The groundwater utilization exceeds the total amount of regional water resources utilization by 50%.In order to rationally develop and utilize the shallow groundwater in Jinghui Canal irrigation area,ensure the food supply in the irrigation area,the fuzzy synthetic optimization evaluation,Wilcox,USSL graphic method and single factor evaluation method were used to evaluate shallow groundwater quality based on 47 shallow groundwater samples in the irrigation area.The results showed that:①The total dissolved solids value of groundwater in the irrigation area was high,the cations was mainly Na^(+),the Ca^(2+)and Mg^(2+)were the second,the anions was mainly SO_(4)^(2-),and the groundwater chemical components were mainly affected by dissolution filtration and concentration.②All the shallow groundwater in Jinghui Canal irrigation area was in class Ⅲ water-level,which was seriously polluted.The long-term irrigation would lead to crop reduction and farmland destruction.The canal water was in class Ⅱ water-level water,which was better than the groundwater and could be accepted for irrigation.③The results of fuzzy comprehensive optimization evaluation were verified by Wilcox,USSL graphic method and single factor evaluation method,which showed that the fuzzy comprehensive optimization model was suitable for groundwater quality evaluation in the study area.This result provides a scientific basis for the management and prevention of groundwater environment in Jinghui Canal irrigation area,and is of great significance to ensure food security in the irrigation area.