SWEMniCS - A Software Toolbox for Modeling Coastal Ocean Circulation, Storm Surges, Inland, and Compound Flooding

Abstract Flooding from storm surges, rainfall runoff, as well as their interaction into compounding events are major natural hazards in coastal regions. To assess risks of damages to human life and properties alike, accurate and flexible numerical models are needed to guide emergency responses as well as long-term risk assessments. High-fidelity numerical models, such as the ADvanced-CIRCulation (ADCIRC) model have over many decades shown their usefulness and promise to perform exactly such assessments. However, these models have a relative high threshold in terms of new user engagement as development and compilation is not trivial for users and programmers trained in compiled programming languages, such as Python or Julia. In this work, we develop a new open-source finite element solver for numerical simulation of coastal, fluvial, and pluvial flooding. The numerical solution procedure of the underlying partial differential equations is developed based on a Python package for FE methods - FEniCSx and uses finite difference schemes to perform temporal discretizations. The goal is to provide a lean framework where new methods and techniques can be rapidly tested for appropriate applications before the cumbersome development into codes such as ADCIRC are undertaken. We demonstrate an validate the developed framework on common shallow water test cases, as well as large-scale computations in the Gulf of Mexico for Hurricane Ike (2008).