The combined risk of extreme tropical cyclone winds and storm surges along the U.S. Gulf of Mexico Coast

Abstract

Tropical cyclones, with their nearshore high wind speeds and deep storm surges, frequently strike the United States Gulf of Mexico coastline influencing millions of people and disrupting offshore economic activities. The combined risk of occurrence of tropical cyclone nearshore wind speeds and storm surges is assessed at 22 coastal cities throughout the United States Gulf of Mexico. The models used are extreme value copulas fitted with margins defined by the generalized Pareto distribution or combinations of Weibull, gamma, lognormal, or normal distributions. The statistical relationships between the nearshore wind speed and storm surge are provided for each coastal city prior to the copula model runs using Spearman's rank correlations. The strongest significant relationship between the nearshore wind speed and storm surge exists at Shell Beach, LA (ρ = 0.67), followed by South Padre Island, TX (ρ = 0.64). The extreme value Archimedean copula models for each city then provide return periods for specific nearshore wind speed and storm surge pairs. Of the 22 cities considered, Bay St. Louis, MS, has the shortest return period for a tropical cyclone with at least a 50 ms−1 nearshore wind speed and a 3 m surge (19.5 years, 17.1‐23.5). The 90% confidence intervals are created by recalculating the return periods for a fixed set of wind speeds and surge levels using 100 samples of the model parameters. The results of this study can be utilized by policy managers and government officials concerned with coastal populations and economic activity in the Gulf of Mexico.

Joint probability risk modelling of storm surge and cyclone wind along the coast of Bay of Bengal using a statistical copula

“…The elliptical copula model with description can be found in Bushra (). This result aligns with those of Trepanier et al (; ), who suggested that Archimedean Gumbel‐based copulas are effective for representing dependence in arbitrarily high dimensions even when only one parameter governs the strength of dependence. Therefore, the Archimedean copula is used to calculate the return periods for wind and surge.…”

“…From these results, it seems that in the BoB, the risk of combined surge heights and wind speeds (even the lowest) are comparably higher than those in the Gulf of Mexico, where Trepanier et al () modelled storm surge and wind‐induced combined risk at Galveston, Texas; and later, at 22 Gulf Coast cities ranging from South Padre Island, Texas, to Key West, Florida (Trepanier et al , ). Rich data availability in the coastal Gulf of Mexico region allowed for a varying spatial picture of combined wind and surge risk in Trepanier et al (). The BoB has a wide‐ranging coastline and likely experiences varying risk similar to the Gulf of Mexico, but due to the sparseness of data, the same level of spatial resolution cannot be attained.…”

“…The BoB has a wide‐ranging coastline and likely experiences varying risk similar to the Gulf of Mexico, but due to the sparseness of data, the same level of spatial resolution cannot be attained. Therefore, localized results should be used with caution and can be compared to the Gulf of Mexico to try and infer potential variability based on risk differences associated with different location types presented in Trepanier et al ().…”

“…Yan () showed that the Gumbel Archimedean and Gaussian elliptical varieties are most effective in their respective families. Trepanier et al () showcased the use and applicability of Archimedean Gumbel‐type copulas at 22 cities around the Gulf of Mexico coastline. The Gumbel Archimedean type is an extreme‐value copula focused on the modelling of joint distributions at the upper‐tail, and after extensive modelling of the varying types, it was shown to be the most suitable for modelling wind and surge dependency at the BoB.…”

“…Mu et al () used copulas for analysing the combined events of seasonal drought and flood in the North China Plain. Only a few studies have examined TC wind and storm surge together (Trepanier, ; Trepanier et al , ; ).…”