ABSTRACT Intensive groundwater use has altered the local hydrological cycle within the Bajío Guanajuatense, Mexico. To improve the knowledge of this hydrogeological system and support water management in the area, groundwater end members were identified using multivariate statistical analysis. Pumped groundwater is composed of two well-mixed end members: (a) recent recharge, affected by a reuse cycle through irrigation where nitrate and chloride evolve and reach levels of 368 mg/L and greater than 100 mg/L, respectively, and (b) deep old groundwater. Mixing estimations show that most wells extract at least 70% of deep groundwater, and some of them extract more than 94%, posing a development and groundwater sustainability conundrum in the area.

中文翻译：

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通过时空同位素和水文地球化学记录识别地下水末端成员

摘要 地下水的密集使用已经改变了墨西哥 Bajío Guanajuatense 的当地水文循环。为了提高对该水文地质系统的了解并支持该地区的水资源管理，使用多变量统计分析确定了地下水终端成员。抽取的地下水由两个混合良好的末端成员组成：(a) 最近的补给，受灌溉再利用循环的影响，其中硝酸盐和氯化物分别演化并达到 368 mg/L 和大于 100 mg/L 的水平，以及 ( b) 较深的古老地下水。混合估计表明，大多数井提取至少 70% 的深层地下水，其中一些井提取了 94% 以上，构成了该地区的开发和地下水可持续性难题。