Coastal Hazards System–Louisiana (CHS-LA)

Abstract

The US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL) expanded the Coastal Hazards System (CHS) to quantify storm surge and wave hazards for coastal Louisiana. The CHS Louisiana (CHS-LA) coastal study was sponsored by the Louisiana Coastal Protection and Restoration Authority (CPRA) and the New Orleans District (MVN), US Army Corps of Engineers (USACE) to support Louisiana’s critical coastal infrastructure and to ensure the effectiveness of coastal storm risk management projects. The CHS-LA applied the CHS Probabilistic Coastal Hazard Analysis (PCHA) framework to quantify tropical cyclone (TC) responses, leveraging new atmospheric and hydrodynamic numerical model simulations of synthetic TCs developed explicitly for the Louisiana region. This report focuses on documenting the PCHA conducted for the CHS-LA, including details related to the characterization of storm climate, storm sampling, storm recurrence rate estimation, marginal distributions, correlation and dependence structure of TC atmospheric-forcing parameters, development of augmented storm suites, and assignment of discrete storm weights to the synthetic TCs. As part of CHS-LA, coastal hazards were estimated within the study area for annual exceedance frequencies (AEFs) over the range of 10 yr-1 to 1×10-4 yr-1.

Statistical analysis of storm surge and seiche hazards for Lake Erie

“…Additionally, the intensity of hazards can be expressed through the AEP, which describes the yearly likelihood that a particular event will transpire within any given year. The AEF differs from the AEP, as documented in Nadal-Caraballo et al (2022). However, the difference between AEF and AEP decreases at the low-frequency tail of the distribution, where events have longer ARI.…”

“…StormSim-PST can output the hazard curve as either annual exceedance probabilities (AEPs) or AEFs. The AEF indicates the expected frequency, in occurrences per year, at which a specific event will meet or surpass a defined threshold (Nadal-Caraballo et al 2022). By calculating the reciprocal of the AEF, where ARI = 1/AEF, one obtains the average recurrence interval (ARI).…”

Tropical or extratropical cyclones: what drives the compound flood hazard, impact, and risk for the United States Southeast Atlantic coast?

“…This method is based on Joint Probability Method (JPM) of the current climate. For more information on the JPM method, refer to Nadal-Caraballo et al (2022). In the present study, the probabilities of the synthetic TCs were updated to reflect climate change in which more intense hurricanes are likely to be observed more frequently in the study area from northern Florida northward.…”

“…For more information on the statistical-corrected GTSM and wave setup, refer to Parker et al (in review). For the TC simulations, water levels from the coupled numerical hydrodynamic and wave model setup (ADCIRC+SWAN; see Nadal-Caraballo et al, 2022), which includes tide, wind-driven surge, and wave-driven setup, were used.…”

Coastal Hazards System–Puerto Rico and US Virgin Islands (CHS-PR)

“…This study provides necessary information related to coastal storm-induced hazards to support coastal engineering and planning activities conducted by the USACE and partners. The CHS-SACS takes advantage of the CHS PCHA framework, which has been implemented in other recent USACE regional coastal studies such as the Coastal Hazards System-Louisiana (CHS-LA) study (Nadal-Caraballo et al 2022) and the Coastal Texas Protection and Restoration Study 1 (CTXS) (Melby et al 2021), leading to consistency of methodology applied and results obtained for US hurricane-exposed coastlines. The PCHA is a statistical and probabilistic framework that builds upon previous joint probability analysis methodologies while incorporating several statistical and machine-learning advancements for more robust and accurate quantification of coastal storm hazards and uncertainty.…”