A total of 7 reference concentration (C₀) models (6 existing and 1 newly proposed) were validated against 119 test cases from 4 recently published datasets collected under the LIP, CROSSTEX, SandT-Pro and SINBAD experimental studies. These models were evaluated for performance in different cross-shore regions: the shoaling zone, breaking (outer surf) zone and inner surf zone, under regular and irregular breaking wave conditions. In almost all existing C₀ models, substantial under-prediction was found particularly around the wave plunging point (point at which breaking wave plunges and surface generated turbulent kinetic energy, TKE, is injected into the water column) where strong localised increases in C₀ were observed. This strong increase in concentration was attributed to the large-scale breaking-generated turbulent vortices invading the wave bottom boundary layer (WBBL) and entraining dense clouds of sediment near the plunging point. Models that were directly or indirectly driven by local wave climate such as the local wave height (H), breaker height (H_b) or local water depth (d), were found to perform quite poorly in the breaking region under regular and irregular plunging breaker waves. Formulations that related C₀ to the sand pickup rate (i.e. depending on exerted bed shear exceeding critical bed shear for entrainment) were adept in regions unaffected by external breaking-induced TKE (e.g. the shoaling zone) but could not account for the high levels of concentration observed at the plunging point. This is because these formulations were based on the implicit assumption that sediment entrainment is only induced by the local TKE generated by bed shear; not taking surface-generated breaking-induced TKE into account. This assumption was addressed in more recent studies, by including breaking-induced TKE into sediment pickup rate or reference concentration formulations. Though latest studies have shown promising relationships between near-bed TKE (k_b) and reference concentration/sediment pickup, such formulations also face inherent limitations. These formulations are highly dependent on the accuracy of measured or modelled k_b and are also sensitive to the magnitude of k_b. For example, the magnitude of measured k_b was found to vary by a factor of 1.1–1.3 between regular and irregular wave conditions, with k_b being smaller under irregular wave conditions. This resulted in varied performance between datasets in k_b-driven reference concentration formulations. The Froude-scaled TKE produced smaller deviations in magnitude of TKE between datasets, suggesting that it may be a more suitable driving parameter for reference concentration models than k_b. A new reference concentration model, L19, was empirically derived from an inverse relationship observed between d and C₀, and from the roller energy dissipation rate. The newly proposed L19 model shows good agreement with measured C₀ (with RMSE ranging between 0.36 and 1.79 kg/m³ over the different datasets) in regular and irregular wave conditions, even at the plunging point where concentration is highest. The modified concentration profile [C(z)] equation also performs well, generally capturing the vertical concentration profile accurately throughout the whole water column.

通过LIP，CROSSTEX，SandT-Pro和SINBAD实验研究收集的4个最近发布的数据集中，针对119个测试案例验证了总共7个参考浓度（C ₀）模型（现有6个模型和1个新提出的模型）。评估了这些模型在不同的跨海岸地区的性能：在规则和不规则的破浪条件下，浅滩区，破碎（外部冲浪）区域和内部冲浪区域。在几乎所有现有的C ₀模型中，尤其是在波切点（破碎波切入点和表面产生湍动能TKE注入水柱的点）附近，都发现了严重的预测不足，C ₀局部强烈增加被观察。浓度的这种强烈增加归因于大规模破坏产生的湍流涡旋侵入波底边界层（WBBL），并在暴跌点附近夹带了厚厚的沉积物云。已直接或间接地由本地波气候驱动诸如本地波高（型号ħ），断路器高度（H ^ _b）或本地水深（d），被发现在断裂区之下规则和不规则的切入相当表现不佳断路器波。与C ₀相关的制剂沙的吸收速率（即取决于施加的床层剪切力是否超过夹带的临界床层剪切力）在不受外部破裂引起的TKE影响的区域（例如，浅滩区）很熟练，但不能解释在暴跌时观察到的高浓度点。这是因为这些公式基于隐含的假设，即泥沙夹带仅是由床剪切产生的局部TKE引起的。没有考虑到表面产生的断裂引起的TKE。通过将诱导的TKE分解为沉积物吸收速率或参考浓度公式，可以解决这一假设。尽管最新研究表明近床TKE（k _b）和参考浓度/沉淀物的提取，此类制剂也面临固有的局限性。这些公式高度依赖于测量或建模的k _b的精度，并且也对k _b的大小敏感。例如，发现在规则和不规则波情况下，测量的k _b的大小相差1.1–1.3，而在不规则波情况下k _b较小。这导致k _b中的数据集之间表现不同驱动的参考浓度配方。Froude缩放的TKE在数据集之间产生了较小的TKE幅度偏差，表明它可能比k _b更适合作为参考浓度模型的驱动参数。根据经验，从d与C ₀之间的反比关系以及滚筒能量耗散率，得出了一个新的参考浓度模型L19 。新提出的L19模型与测得的C ₀表现出良好的一致性（RMSE介于0.36和1.79 kg / m ^3之间）在规则和不规则波浪条件下，即使在浓度最高的下降点也是如此。修改后的浓度分布[ C（z）]方程也表现良好，通常可以准确地捕获整个水柱中的垂直浓度分布。