Abstract The increasing demand for water and irrigation in the semi-arid Bolivian Altiplano requires a better knowledge of the available resources, particularly groundwater. The aim of this study is to provide a first insight into the hydrogeological structure (0–200 m deep) and groundwater dynamics of the Katari-Lago Menor Basin aquifer located between the Eastern Cordillera and Lake Titicaca, Bolivia. This aquifer is studied using geophysical data (a total of 187 Time Domain Electromagnetic (TDEM) soundings), piezometric data (97 groundwater level measurements) and geochemical data (52 groundwater samples), combined with geological, lithological and topographical information. The results allowed identifying stratigraphic models consistent with the Quaternary sediments being hydraulically connected and behaving as a single regional basin-aquifer. This basin-aquifer is delimited by the most ancient lake invasions towards the southern, western and northern sides and by the lower limit of rock glaciers towards the eastern side. A large portion of the aquifer presents an unconfined behaviour varying from 50 to 150 m while the confined portion varies from 100 to 150 m. Groundwater flow within the Katari and Lago Menor Basin aquifer is composed of several interconnected groundwater flow systems. The main groundwater flow system starts in the high mountain ranges of the Eastern Cordillera, follows the topographic Piedmont gradient (NE to SW) and discharges in a series of wetlands. This multidisciplinary approach proved to be an appropriate method to derive a consistent picture of the hydrogeological functioning of the Katari-Lago Menor Basin aquifer.

中文翻译：

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从地球物理 (TDEM)、水文地质和地球化学数据推断，深入了解 Katari-Lago Menor 盆地含水层、的喀喀湖-玻利维亚

摘要 玻利维亚半干旱高原对水和灌溉的需求不断增加，需要更好地了解可用资源，尤其是地下水。本研究的目的是初步了解位于东科迪勒拉山脉和玻利维亚的喀喀湖之间的 Katari-Lago Menor 盆地含水层的水文地质结构（0-200 m 深）和地下水动态。使用地球物理数据（总共 187 次时域电磁 (TDEM) 测深）、测压数据（97 次地下水位测量）和地球化学数据（52 次地下水样本），结合地质、岩性和地形信息来研究该含水层。结果允许识别与第四纪沉积物相一致的地层模型，这些沉积物通过水力连接并表现为单一的区域盆地-含水层。该盆地含水层由向南、西和北侧的最古老的湖泊入侵以及向东侧的岩石冰川的下限划定。含水层的很大一部分表现出从 50 到 150 m 不等的非承压行为，而承压部分从 100 到 150 m 不等。Katari 和 Lago Menor 盆地含水层内的地下水流由几个相互关联的地下水流系统组成。主要的地下水流系统始于东科迪勒拉山脉的高山山脉，顺着地形皮埃蒙特梯度（东北至西南）并在一系列湿地中排放。事实证明，这种多学科方法是获得一致的 Katari-Lago Menor 盆地含水层水文地质功能图的合适方法。