Morphodynamics, subsurface flow and transport

DynaDeep将揭示高能海滩下海洋-陆地相互作用的功能和相关性，在那里，我们提出深层地下作为一个动态生物反应器和独特的微生物栖息地，影响到海洋的元素净通量。为了实现这一目标，六个次级项目将在联合实地运动、共享抽样方法和实验工作方面进行合作，并在综合方法中使用数学模型。子项目P1将研究地下水的流动和运输模式，作为水动力学和形态动力学的函数。我们假设，潮汐影响下地下河口的地下水流量和盐度分布的最新概念不适用于高能海滩。相反，我们期望高度瞬态的流动条件，在盐度、流动方向和停留时间方面具有高频率和高幅度的变化。P1将使用相机成像、激光扫描和无人机来调查海滩和前海岸的形态。野外观测将与数值模型相结合，得出海滩形态的典型适应时间和长度尺度。地球物理方法可以快速、无创地识别地下盐度模式及其随时间的变化。环境示踪剂数据将用于估计地下停留时间。来自STE在线观测站的形态、水文（地理）逻辑和地球物理数据将用于数值地下水流动和输送模型，以提供STE内瞬态流动和输送模式的全面图景。这些关于水体分布、流速、停留时间和混合程度的知识将为子项目P2-P6的生物地球化学调查提供基础。

DynaDeep will unravel the functionality and relevance of marine-terrestrial interactions below high-energy beaches, where we propose the deep subsurface to act as a dynamic bioreactor and unique microbial habitat affecting elemental net fluxes to the sea. To reach this goal, six subprojects will cooperate in joint field campaigns, shared sampling approaches as well as experimental work and use mathematical models in an integrative approach. Subproject P1 will study groundwater flow and transport patterns as a function of hydro- and morphodynamics. We hypothesize that the state-of-the-art concept of groundwater flow and salinity distribution in subterranean estuaries under tidal influence does not hold for high-energy beaches. Instead, we expect highly transient flow conditions, with high frequencies and amplitudes of change in salinities, flow directions and residence times. P1 will survey beach and foreshore morphology using camera imaging, laser-scanning and drones. Field observations will be combined with numerical models to derive typical adaptation time- and length scales of the beach morphology. Geophysical methods will enable a fast and non-invasive way of identifying subsurface salinity patterns and their change over time. Environmental tracer data will be used to estimate subsurface residence times. Morphological, hydro(geo)logical and geophysical data from the STE Online Observatory will be utilized in numerical groundwater flow and transport modelling to provide a comprehensive picture of transient flow and transport patterns within the STE. This knowledge on the distribution of water bodies, flow velocities, residence times and extent of mixing will provide the basis for biogeochemical investigations carried out in subprojects P2-P6.