GroMoPo Metadata for Bremerhaven coastal aquifer model

Climate change is expected to induce sea level rise in the German Bight, which is part of the North Sea, Germany. Climate change may also modify river discharge of the river Weser flowing into the German Bight, which will alter both pressure and salinity distributions in the river Weser estuary. To study the long-term interaction between sea level rise, discharge variations, a storm surge and coastal aquifer flow dynamics, a 3D seawater intrusion model was designed using the fully coupled surface-subsurface numerical model HydroGeoSphere. The model simulates the coastal aquifer as an integral system considering complexities such as variable-density flow, variably saturated flow, irregular boundary conditions, irregular land surface and anthropogenic structures (e.g., dyke, drainage canals, water gates). The simulated steady-state groundwater flow of the year 2009 is calibrated using PEST. In addition, four climate change scenarios are simulated based on the calibrated model: (i) sea level rise of 1 m, (ii) the salinity of the seaside boundary increases by 4 PSU (Practical Salinity Units), (iii) the salinity of the seaside boundary decreases by 12 PSU, and (iv) a storm surge with partial dyke failure. Under scenarios (i) and (iv), the salinized area expands several kilometers further inland during several years. Natural remediation can take up to 20 years. However, sudden short-term salinity changes in the river Weser estuary do not influence the salinized area in the coastal aquifer. The obtained results are useful for coastal engineering practices and drinking water resource management. (C) 2015 Elsevier B.V. All rights reserved.

预计气候变化将导致德国湾海平面上升，德国湾是北海的一部分。气候变化还可能改变流入德国湾的威悉河的径流量，这将改变威悉河河口的水压和盐度分布。为了研究海平面上升、径流变化、风暴潮以及海岸含水层流动力学的长期相互作用，设计了一个基于完全耦合地表-地下数值模型HydroGeoSphere的3D海水入侵模型。该模型将海岸含水层视为一个整体系统，考虑了诸如可变密度流、非饱和流、不规则边界条件、不规则地表以及人为结构（例如海堤、排水渠、水闸）等复杂性。利用PEST对2009年的稳定地下水流动进行了校准。此外，基于校准模型模拟了四种气候变化情景：（i）海平面上升1米，（ii）海边边界盐度增加4 PSU（实际盐度单位），（iii）海边边界盐度降低12 PSU，以及（iv）部分海堤失效的风暴潮。在情景（i）和（iv）下，盐化区域在数年内向内陆扩展数公里。自然修复可能需要长达20年。然而，威悉河河口短期内盐度的突然变化并不会影响海岸含水层中的盐化区域。获得的结果对海岸工程实践和饮用水资源管理具有实用性。（C）2015 Elsevier B.V. 版权所有。