Coastal flooding is a growing hazard. Compound event characterization and uncertainty quantification are critical to accurate flood risk assessment. This study presents univariate, conditional, and joint probabilities for observed water levels, precipitation, and waves. Design events for 10‐ and 100‐year marine water level and precipitation events are developed. A total water level formulation explicitly accounting for wave impacts is presented. Uncertainties associated with sampling method, copula selection, data record length, and utilized rainfall gauge are determined. Eight copulas are used to quantify multivariate uncertainty. Generally, copulas present similar results, except the BB5. Sampling method uncertainty was quantified using four sampling types; annual maximum, annual coinciding, wet season monthly maximum, and wet season monthly coinciding sampling. Annual coinciding sampling typically produced the lowest event magnitude estimates. Uncertainty associated with record length was explored by partitioning a 100‐year record into various subsets. Withholding 30 years of observations (i.e., records of less than 70 years) resulted in substantial variability of both the 10‐ and 100‐year return period estimates. Approximately equidistant rainfall gauges led to large event estimate differences, suggesting microclimatology and gauge selection play a key role in characterizing compound events. Generally, event estimate uncertainty was dominated by sampling method and rainfall gauge selection.

中文翻译：

---

量化波浪和潮汐主导的沿海地区复合洪水事件的不确定性：系词选择、采样、记录长度和降水量计选择的影响

沿海洪水的危害日益严重。复合事件表征和不确定性量化对于准确的洪水风险评估至关重要。这项研究提出了观测到的水位、降水和波浪的单变量、条件和联合概率。开发了 10 年和 100 年海水水位和降水事件的设计事件。提出了明确考虑波浪影响的总水位公式。确定与采样方法、联结选择、数据记录长度和所使用的降雨量计相关的不确定性。八个连接函数用于量化多元不确定性。一般来说，除了 BB5 之外，联结函数呈现相似的结果。使用四种采样类型对采样方法的不确定性进行量化；年最大值、年度重合、雨季月最大值和雨季月重合采样。年度一致采样通常会产生最低的事件震级估计。通过将 100 年记录划分为不同的子集，探索了与记录长度相关的不确定性。保留 30 年的观测（即少于 70 年的记录）导致 10 年和 100 年重现期估计值存在很大差异。大约等距的雨量计导致事件估计存在较大差异，这表明微气候学和雨量计的选择在表征复合事件方面发挥着关键作用。一般来说，事件估计的不确定性主要取决于采样方法和雨量计的选择。