Abstract Dunes are key elements of coastal landscapes in almost every latitude. They host high levels of biodiversity and provide important benefits to society; e.g. protection against floods and erosion, or recreation. Coastal dune growth is constrained by intrinsic factors, which are critical when managing dune systems or choosing coastal dune restoration as an alternative green solution for coastal protection. Here, the evolution of a beach-dune system, characterized by a reflective coarse sandy beach and low dunes, is explored to identify the favourable and optimal conditions for dune growth in these settings. Dune growth capacity is evaluated by analysing the topographical changes observed along a coastal dune over two different temporal scales (interannual and event scale) and comparing the observations with theoretical approximations of sediment transport potentials. Observations and predictions over interannual scale document that (1) temporal variability in external conditions (wind regime) and spatial variability of estimated wind fetch length, alone, fail to explain alongshore dune growth patterns and (2) optimal conditions for dune growth occur when storms (strong winds) impact the study area, jointly with low runup levels, at zones of shoreline progradation and absence of direct human influence. Conversely, lowest values of dune accumulation are associated with areas where shoreline retreat was documented. Observations from event timescales suggest that sediment transport potential can be reached over zones with no significant signs of beach erosion, if runup levels remain low and the event duration is shorter than the time scale of sand surface depletion within the upper beach.

中文翻译：

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探索粗沙滩的前生生长能力

摘要 沙丘是几乎所有纬度的沿海景观的关键元素。它们拥有高水平的生物多样性并为社会提供重要利益；例如，防止洪水和侵蚀，或娱乐。沿海沙丘的生长受到内在因素的限制，这些因素在管理沙丘系统或选择沿海沙丘恢复作为沿海保护的替代绿色解决方案时至关重要。在这里，探索了以反射性粗糙沙滩和低沙丘为特征的海滩沙丘系统的演变，以确定在这些环境中沙丘生长的有利和最佳条件。通过分析沿海岸沙丘在两个不同时间尺度（年际和事件尺度）上观察到的地形变化，并将观察结果与沉积物输送潜力的理论近似值进行比较，评估沙丘生长能力。年际尺度的观测和预测表明：(1) 外部条件（风况）的时间变化和估计的风取长度的空间变化，单独无法解释沿岸沙丘生长模式，以及 (2) 风暴发生时沙丘生长的最佳条件（强风）在海岸线前移和没有直接人类影响的区域影响研究区域，同时具有低上升水平。相反，沙丘堆积的最低值与记录到海岸线后退的地区有关。