Can Anthropogenic Barrier Island and Shelf Modifications Alter Estuary Storm Tides?

Abstract:

Storm tides in New York/New Jersey Harbor have increased in height significantly since the 1800s, correcting for the additional effect of rising sea levels. However, studies have failed to produce evidence that this was caused by climate change, or dredging and landfill in the harbor region. Here, we will test whether various types of anthropogenic modifications to barrier islands and the continental shelf can explain these historical changes, or could cause changes in the coming decades. Historical development on and buttressing of barrier islands and peninsulas could reduce overtopping and flooding of back-bays. Not only are the barriers changed, but sediment is moved from offshore onto the beach, deepening and smoothing the shallow shelf. The effects of these changes will be tested using storm tide simulations with a detailed northwest Atlantic hydrodynamic model that includes floodplains, using a “present-day” landscape and estimated changes to the barrier systems and shelf to represent a natural, undeveloped landscape. Additional simulations will be used to similarly investigate the effects on storm tides of future sea level rise and possible human response adaptations (e.g. raised barrier island berms and gated surge barriers across back-bay inlets).