Depth of closure (DOC) is a commonly-used parameterization of the seaward limit in significant elevation change along a beach profile. Engineers, scientists, and resource managers use this parameter to make decisions and formulate designs for activities ranging from ecological restorations to beach nourishment and harbor construction. We present empirically measured DOC values from eight sites along the U.S. East Coast from Long Island NY to Georgia. The sites represent a spectrum of settings between fully wave-dominant and mixed-energy barriers and beaches, and five of the eight surveys extend back at least one decade. There are multiple DOC formulations based on wave conditions that tend to over-estimate DOC values compared to empirical observations. Our results show a similar pattern, with modeled DOC averaging 2.5 m (m) deeper than surveyed values but yielding reasonable results in wave-dominant environments. Along mixed-energy sites, modeled DOC values range from 1.0 to 5.7 m deeper than empirical observations. Alongshore comparison of observed DOC values within individual sites also suggests the movement of shoals on the lower shoreface near inlets may further complicate DOC estimates compared to strand-type shorelines with relatively featureless nearshore slopes.

闭合深度 (DOC) 是沿海滩剖面显着高程变化时向海限制的常用参数化。工程师、科学家和资源经理使用此参数为从生态恢复到海滩营养和港口建设等活动做出决策和制定设计。我们展示了从纽约长岛到乔治亚州沿美国东海岸的八个地点的经验测量 DOC 值。这些地点代表了完全以波浪为主导和混合能源障碍和海滩之间的一系列环境，八项调查中的五项至少可以追溯到十年前。有多种基于波浪条件的 DOC 公式，与经验观察相比，这些公式往往会高估 DOC 值。我们的结果显示了类似的模式，建模的 DOC 平均为 2。比测量值深 5 m (m)，但在波浪主导的环境中产生合理的结果。沿着混合能源站点，模拟的 DOC 值范围比经验观察深 1.0 到 5.7 m。对单个站点内观测到的 DOC 值的沿岸比较也表明，与具有相对无特征的近岸斜坡的搁浅型海岸线相比，靠近入口的下岸面浅滩的运动可能使 DOC 估计进一步复杂化。