考虑海平面上升影响的极值水位计算

本研究基于非平稳序列极值理论,定量分析极端水位事件年超越概率受海平面上升的影响;以工程设计使用年限内极端水位发生概率作为控制条件,构建考虑海平面上升的极值水位计算方法;结合平均海平面的长期变化过程,推算海平面上升下的极值水位。基于全球10个验潮站历史水位观测资料,验证历史平均海平面长期变化与高、低水位耿贝尔分布位置参数变化的一致性以及构建方法的合理性。结合政府间气候变化专门委员会对海平面上升的预测,推算和对比分析不同海平面上升情景下的极值水位,并评估相应极值水位在当前极值分布中的重现期。

Calculation of extreme water level with the effect of sea level rise

Based on the extreme value theory of non-stationary sequences, this study carried out the quantitative analysis of the effect of sea level rise on the exceedance probability of extreme water levels. A new method for the estimation of extreme water level with sea level rise was proposed by adopting the overall exceedance probability of extreme water level within the design lifetime of coastal facilities as a critical constraint. With the incorporation of sea level rise in the location parameter of Gumbel distribution, the new method allows the adjustment of the annual exceedance probability of extreme water levels along with sea level rise over time. The validity of the proposed method was examined using the long term sea level measurement data at 10 tide gauge stations globally. Using the five global mean sea level rise scenarios projected by IPCC, the extreme water levels for different design lifetime of coastal facilities with sea level rise were estimated, and the return periods of the extreme water levels were also evaluated.