Assessment of ADCIRC’s Wetting and Drying Algorithm

The ADvanced CIRCulation (ADCIRC) model is a finite-element hydrodynamic model based on the generalized wave continuity equation (GWCE). The model assumed fixed land boundaries until a wetting and drying algorithm was implemented by Luettich and Westerink in 1995 [1,2]. The algorithm uses an element-based approach, effectively turning elements on and off based on water depths and a water level gradient. While robust in some simulations, the algo-rithm can be subject to instabilities in the solution during highly nonlinear events. Thus, a rigor-ous assessment of the algorithm’s stability, accuracy, mass balance properties, and parameter sensitivity under a variety of conditions is needed. Herein, we examine these issues using a one-dimensional implementation of the wetting and drying algorithm for basins with a linear slope; future studies will examine a wider variety of real and idealized basins. We believe the results of this work will benefit similar studies in two- or three-dimensions, for users and developers of both ADCIRC and other finite element models. 1. BACKGROUND Shallow water equations are used by researchers and engineers to model the hydrody-namic behavior of oceans, coastal areas, estuaries, lakes and impoundments [3]. The finite ele