Abstract This review concerns the knowledge of the isotopic composition of current precipitation and its association with climate, geography and orography, in the Central Andes (14–28°S and 75–63°W). This knowledge is required for the evaluation of other hydrological values, especially aquifer recharge and water resources, in environments varying from rainy to hyper-arid. Since the 1960s, oxygen (δ18O) and deuterium (δ2H) isotope composition of natural water have been used as tracers of the global hydrological cycle. In the present article, the goal is to identify the origin and trajectory of air masses that produce rainfall in the Central Andes and the isotopic composition of the precipitation, as a first step to evaluate recharge and groundwater resources. The isotopic composition of rainfall varies spatially and temporarily, depending on the climatic phenomena that originate the movement of air masses, their moisture content and the isotope fractionation processes that occur until precipitation falls. Most of the significant and recent literature on the mechanisms of δ18O and δ2H transport and fractionation in precipitation along the Central Andes has been collected and summarized in this review. Precipitation in the eastern and central Andes comes mainly from the humidity generated in the Atlantic Ocean. Although the processes involved in isotope content variability of precipitation are well known, the processes involved in isotopic variability in the Western Cordillera remain poorly understood. This is mostly due to mixing of different moisture sources: from the Atlantic Ocean in summer and from the Pacific Ocean in winter. In general, winter rainfall is more enriched in δ18O and δ2H than summer rainfall. Looking at existing data, their distribution is far from being homogeneous and well-distributed, so spatial accuracy is poor in some areas, especially in the Altiplano. Hydrological and hydrogeological research and water resources evaluation in the Central Andes would greatly benefit from initiatives to obtain broader spatial coverage of rainfall collection to get isotope data for more accurate and continuous assessment of the local weather patterns. Groundwater isotope composition is a future tool to help in increasing the coverage in data scarce areas.

中文翻译：

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中部安第斯山脉降水氧氢同位素组成的起源和变异性：综述

摘要 本综述涉及中安第斯山脉（14-28°S 和 75-63°W）当前降水同位素组成的知识及其与气候、地理和地形的关联。在从多雨到极度干旱的环境中评估其他水文价值，尤其是含水层补给和水资源，需要这些知识。自 1960 年代以来，天然水的氧 (δ18O) 和氘 (δ2H) 同位素组成已被用作全球水文循环的示踪剂。在本文中，目标是确定在安第斯中部产生降雨的气团的起源和轨迹以及降水的同位素组成，作为评估补给和地下水资源的第一步。降雨的同位素组成在空间上和暂时性上发生变化，取决于引起气团运动的气候现象、它们的水分含量以及在降水下降之前发生的同位素分馏过程。在这篇综述中收集和总结了大多数关于 δ18O 和 δ2H 迁移和沿安第斯山脉降水分馏机制的近期重要文献。安第斯山脉东部和中部的降水主要来自大西洋产生的湿气。尽管涉及降水同位素含量变异的过程是众所周知的，但对西科迪勒拉同位素变异涉及的过程仍然知之甚少。这主要是由于不同水分来源的混合：夏季来自大西洋，冬季来自太平洋。一般来说，冬季降水比夏季降水更富含δ18O和δ2H。从现有数据来看，它们的分布远非均匀分布，因此某些地区的空间精度较差，尤其是高原地区。中部安第斯山脉的水文和水文地质研究以及水资源评估将极大地受益于获得更广泛的降雨收集空间覆盖范围的举措，以获得同位素数据，从而更准确和连续地评估当地天气模式。地下水同位素组成是未来有助于增加数据稀缺地区覆盖范围的工具。中部安第斯山脉的水文和水文地质研究以及水资源评估将极大地受益于获得更广泛的降雨收集空间覆盖范围的举措，以获得同位素数据，从而更准确和连续地评估当地天气模式。地下水同位素组成是未来有助于增加数据稀缺地区覆盖范围的工具。中部安第斯山脉的水文和水文地质研究以及水资源评估将极大地受益于获得更广泛的降雨收集空间覆盖范围的举措，以获得同位素数据，从而更准确和连续地评估当地天气模式。地下水同位素组成是未来有助于增加数据稀缺地区覆盖范围的工具。