Coastal Modeling Considerations for Compound Flooding Events at Three Flood Risk Management Projects in Coastal Texas
Abstract
The US Army Corps of Engineers builds, operates, and maintains many coastal flood risk management (CFRM) projects around the United States. To evaluate the design effectiveness and operation of these CFRM projects requires applying high fidelity numerical modeling of the relevant coastal and inland processes, within a probabilistic framework of forcing events. This includes considering compound flooding (CF) events for CFRM project design and evaluation. In this context, CF events are where and when storm surge and waves combine and interact with fluvial and pluvial flooding with the potential to increase total flood levels, either from the same event or from back to back events. Climate change variability further complicates and exacerbates the issue for many locations. Understanding how to statistically represent probabilities of CF events and in turn how to properly and efficiently model those for CFRM studies are two main focus areas of research and development. The Coastal Storm Modeling System (CSTORM-MS) framework has greatly improved the accuracy and efficiency of coastal storm surge and wave modeling capabilities. Such efficiencies are important in CFRM studies as the number of storm conditions accounting for variabilities in storm forcing for wind speeds, atmospheric pressure, storm size and forward speed combined with sea level rise scenarios are already required and if CF events are include, precipitation amounts/rates and river stage level variations must also be included. This means to achieve suitable levels of accuracy for engineering design of CFRM structures, ten's to hundreds are more simulations will be required. Therefore, quantifying under what conditions it is important to apply model coupling/applications between coastal and riverine/runoff models is critical.
This presentation provides details on impacts to coastal flooding levels for three locations in relatively close proximity of each other along the US Texas coast. Examples of total floodwater sensitivities to CF considerations on the coastal water level responses will be presented for both historical storms and synthetic storm events. Numerical models from these case studies include CSTORM coupled ADCIRC and STWAVE for surge and waves.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFMNH36A..02M