Analysis of Ship-Generated Hydrodynamic Characteristics in the Delaware River

Estuaries and coastal waterways have long been used as shipping channels for inland ports to reduce overland transport and provide natural protection against open water conditions. Inherently, these waterway systems are low energy intensive environments due to their finite depth and limited fetch. The shorelines and wetland areas in these environments have been naturally developed as a buffer to attenuate local hydrodynamic forces. However, repetitive wave forces generated by large ship wakes propagating through narrow and shallow channels can disrupt the natural morphology of nearby shorelines and wetlands due to their relatively large magnitude compared to ambient fluvial conditions. Additionally, the threat of human activity induced erosion is amplified in these regions by sea level rise and worsening storms. This study investigates the complex hydrodynamic characteristics of ship generated wakes and quantifies the associated energies experienced by the shoreline on Pea Patch Island in New Castle County, Delaware. To perform this analysis, a month-long instrumented field study was conducted on the shoreline of Pea Patch Island adjacent to the main shipping channel of the Delaware River. The data collected in the study were used to inspect the energy transferred from individual wake events caused by passing ships and compared with the energy associated with ambient river conditions. The fully nonlinear Boussinesq model, FUNWAVE, was used with varying ship parameters and background conditions consistent with field collected data to quantify model skill and the model's ability to predict the impacts of increased shipping activity under present and anticipated sea lever rise scenarios. Preliminary results of the model and comparisons to the measured data will be presented.