GroMoPo Metadata for Nauru Island model

Water resources sustainable management is a vital issue for small islands where groundwater is often the only available water resource. Nauru is an isolated and uplifted limestone atoll island located in the Pacific Ocean. Politecnico di Milano performed a feasibility study for the development of sustainable use of groundwater on the island. This paper focuses on the first phase of the study that concerns the conceptual site model development, the hydrogeological characterization and the 2D model implementation. During the project, different activities were performed such as GNSS topographic survey of monitoring wells and groundwater level surveys taking into account tidal fluctuation. This data collection and the analysis of previous studies made it possible to identify the most suitable areas for groundwater sustainable extraction. The characterization findings suggested, unlike previous studies and surveys, the presence of only few drought resilient thin freshwater lenses, taking place in low conductivity sandy deposits, unexpectedly next to the seashore. Thanks to the 2D modeling results, it has been possible to clarify the mechanism that allows the storage of freshwater so close to the sea.水资源可持续管理对于小型岛屿而言是至关重要的议题，这类岛屿的地下水往往是唯一可获取的水资源。瑙鲁是坐落于太平洋的孤立抬升石灰岩环礁岛屿。米兰理工大学（Politecnico di Milano）针对该岛屿的地下水可持续利用开展了可行性研究。本文聚焦于该研究的第一阶段，内容涵盖场地概念模型构建、水文地质特征表征以及二维模型（2D model）的搭建与实现。本项目期间开展了多项工作，包括监测井的GNSS（全球导航卫星系统，Global Navigation Satellite System）地形测量，以及考虑潮汐波动影响的地下水位监测。通过本次数据采集与既往研究分析，得以确定最适宜开展地下水可持续开采的区域。水文地质表征结果显示，与既往研究及勘测结果不同，仅存在少量耐旱的薄淡水透镜体，它们赋存于低导水率的砂质沉积物中，且意外地紧邻海岸。借助二维模型的模拟结果，得以阐明淡水能够在如此贴近海洋的区域储存的机理。