This study investigates the mechanisms of dune formation and growth on a micro-tidal beach. The study area, located on a barrier island on the northern Yucatan peninsula, is characterized by persistent sea breeze conditions and a wide and shallow continental shelf. Beach topography data was collected over 5 years, on a prograding beach (0.5–7 m y^-1), using a Real-Time Kinematic Differential Global Positioning System. The beach surveys (>100) cover from the subaerial beach (seaward from the existing foredune in 2015) to a 1.5 m water depth with a high spatial (0.2 m–0.5 m) and temporal (weekly to bi-weekly) resolution. Thus, shoreline evolution, offshore/onshore inner sandbar migration, and foredune initiation and growth can be analyzed from this data set. Moreover, environmental conditions, obtained from in situ observations and numerical model simulations, allow us to investigate the role of marine and aeolian processes on foredune morphodynamics. A net shoreline advance is observed, induced by the presence of a port's jetty, allowing the formation of a new foredune during the period of study. Field observations suggest that seasonal beach variability is explained by the onshore (offshore) sediment transport during fall-winter (spring-summer). The dune growth rate is well correlated with the monthly mean wind speed that reaches a maximum during spring months, when sea-breezes are more persistent and intense (W > 12 m s^-1), the effective fetch length is larger, and the moisture content is lower. Empirical Orthogonal Function (EOF) analysis of beach profiles in the fast progradation area (>1 m y^-1) shows that the variability is dominated by sustained beach width increase throughout the study period. On the other hand, at the slow progradation area the first and second EOF modes explain the seasonal beach and foredune variability, respectively. Thus, it is suggested that beach sand supply (during fall-winter) followed by aeolian transport (during spring) control the natural foredune growth in this region.

本研究调查了微潮海滩上沙丘的形成和生长机制。研究区位于尤卡坦半岛北部的一个障壁岛上，其特点是持续的海风条件和宽而浅的大陆架。海滩地形数据是在 5 年多的时间里收集的，在一个退化的海滩上（0.5-7 my ^-1)，使用实时动态差分全球定位系统。海滩调查 (>100) 覆盖从地面海滩（从 2015 年现有前缘向海）到 1.5 m 水深，具有高空间（0.2 m–0.5 m）和时间（每周到每两周）分辨率。因此，可以从该数据集分析海岸线演化、近海/陆上内部沙洲迁移以及前缘开始和生长。此外，从原位观测和数值模型模拟获得的环境条件使我们能够研究海洋和风成过程对前尾形态动力学的作用。观察到由港口码头的存在引起的净海岸线前进，允许在研究期间形成新的前缘。实地观察表明，季节性的海滩变异是由秋冬季（春夏季）的陆上（近海）沉积物迁移来解释的。沙丘增长率与在春季达到最大值的月平均风速密切相关，此时海风更加持久和强烈（W  > 12 m s ^-1 )，有效取长度较大，含水量较低。快速进积区 (>1 my ^-1 )海滩剖面的经验正交函数 (EOF) 分析表明，在整个研究期间，可变性主要由持续的海滩宽度增加决定。另一方面，在缓慢进积区，第一和第二 EOF 模式分别解释了季节性海滩和前缘变化。因此，建议海滩沙供应（秋季-冬季）和风沙输送（春季）控制了该地区的自然前缘生长。