A basis function approach for exploring the seasonal and spatial features of storm surge events

作者：Wu Wenyan^*; Westra Seth; Leonard Michael

来源：Geophysical Research Letters, 2017, 44(14): 7356-7365.

DOI：10.1002/2017GL074357

Storm surge is a significant contributor to flooding in coastal and estuarine regions. To represent the statistical characteristics of storm surge over a climatologically diverse region, we propose the use of basis functions that capture the temporal progression of individual storm surge events. This extends statistical analyses of surge from considering only the peak to a more multifaceted approach that also includes decay rate and duration. Our results show that there is seasonal variation in storm surge along the Australian coastline. During the dominant storm surge seasons, the peak and duration of storm surge events tend to increase simultaneously at a number of locations, with implications for flood damage assessments and evacuation planning. By combining the dynamic and statistical features of storm surge, it is possible to better understand the factors that can lead to flood risk along the coastline, including estuarine areas that are also affected by fluvial floods.
Plain Language Summary Storm surge is the increase in ocean water levels due to low pressure and wind stress acting on the ocean's surface. It is an important contributor to flooding in coastal and estuarine regions, and it is critical to understand the risks related to these events. Storm surge-related risk is often estimated using statistical methods, where only the peak of the surge is considered. However, storm surge is a dynamic process that can last from hours to days. It is important to understand not only the peak but also how these events evolve. In other words, the duration of surge events and how quickly they grow and decay over time. In this study, a new approach is proposed to extend the statistical analysis of storm surge from only the peak to including duration and decay information. By testing surge data from 15 tide gauges around Australia, we found that storm surge varies significantly during different times of the year along the Australian coastline. During dominant seasons, surge events with higher peaks tend to last longer, resulting in extended flood damage and disruption.

• 出版日期2017-7-28