Data pertaining to 'Dunedin groundwater monitoring, spatial observations and forecast conditions under sea level rise'

Dunedin City in the South Island of New Zealand has many assets and critical infrastructure sitting on a low-lying coastal plain that is underlain by a largely unseen and relatively poorly understood hazard. Shallow groundwater in this area limits the unsaturated ground available to store rain and runoff, promotes flooding and creates opportunities for infiltration into stormwater and wastewater networks. Groundwater levels are expected to rise as sea level rises, causing greater frequency of flooding and/or direct inundation once it nears the ground surface. This zipped archive contains ArcGIS 10.8 geodatabases and spatial analysis of data gathered from a shallow groundwater monitoring network between 6/3/2019 and 1/5/2023. A series of statistical surfaces represent the present-day (2023) water table elevation and depth to groundwater, the response to rainfall recharge and tidal forcing, the available subsurface storage of rain infiltration. Simple geometric models have also been developed using the present shape and position of the water table, combined with tidal fluctuations, to forecast the future state of groundwater levels at 10 cm increments of sea level rise (up to 1 m). The geometric models are strongly empirical, with many implicit assumptions and caveats – particularly, that they do not account for groundwater flow and possible changes in water-budget mass balance. Although many variables and controlling processes are simplified into a single parameter, the projected groundwater levels highlight how local variations in the water table shape and slope interact locally with the ground elevation or infrastructure networks. They are best considered as a worst-case analysis of groundwater-related contribution to hazard and how this will evolve over time. Data are licensed under Creative Commons Attribution 4.0 (CC-BY-4.0) license without warranty. Further description of these data, and implications from the analysis, can be found in the GNS Science metadata catalogue https://data.gns.cri.nz/metadata/srv/eng/catalog.search#/metadata/06a86338-a0fa-436f-9c80-2d8da1dcd64f oe Cox et al. (2023) GNS Science Report 2023/43 doi:10.21420/5799-N894.新西兰南岛达尼丁市（Dunedin City）的诸多资产与关键基础设施均坐落于低洼沿海平原之上，该平原下方隐藏着一种鲜为人知、研究相对不足的灾害隐患。本区域的浅层地下水（shallow groundwater）会限制非饱和土层储存雨水与径流的能力，加剧洪涝风险，并为雨水和污水管网的入渗创造条件。随着海平面上升，地下水位预计将抬升，一旦地下水位接近地表，将导致洪涝发生频率增加，甚至出现直接淹没情况。 本压缩归档包含ArcGIS 10.8地理数据库（geodatabases），以及基于2019年3月6日至2023年5月1日期间浅层地下水监测网络采集数据开展的空间分析成果。一系列统计曲面分别表征了当前（2023年）的地下水位高程与地下水埋深、降雨补给与潮汐强迫响应、雨水入渗的地下可用存储空间。 研究团队还基于当前地下水位的形态与位置，结合潮汐波动，构建了简单几何模型，用于预测海平面每上升10厘米（最高至1米）时的地下水位未来状态。该几何模型属于高度经验性模型，存在诸多隐含假设与限制条件——尤其未考虑地下水流过程以及水收支质量平衡的潜在变化。尽管诸多变量与控制过程被简化为单一参数，但预测的地下水位仍清晰展现了地下水位形态与坡度的局部变化如何与地面高程或基础设施网络产生局部交互作用。本分析可视为地下水相关灾害贡献的最坏情景分析，及其随时间演变的趋势参考。 本数据集采用知识共享署名4.0（Creative Commons Attribution 4.0，CC-BY-4.0）许可协议发布，不提供任何担保。关于这些数据的详细说明与分析结论，可参阅GNS Science元数据目录：https://data.gns.cri.nz/metadata/srv/eng/catalog.search#/metadata/06a86338-a0fa-436f-9c80-2d8da1dcd64f，以及考克斯（Cox）等人（2023）发表的《GNS Science报告2023/43》，DOI：10.21420/5799-N894。