An Integrated Method for Monitoring Material Transport in a Coupled Land-Estuary System Following a Dynamic Storm Event : The Neuse River and Estuary, NC and Hurricane Irene

Abstract

Coastal aquatic environments are complex and dynamic systems that are influenced by both marine and terrestrial processes such as waves, tides, winds and freshwater discharge. Rivers are conduits that transport freshwater and terrestrially derived particulate and dissolved material such as sediment and dissolved organic matter (DOM) to the coastal ocean. Increased concentrations of these in-water constituents can negatively influence aquatic biota. Storm events and associated rainfall often lead to increases in the amount of terrestrial material delivered to coastal waters, however varying storm characteristics such as the location and intensity of rainfall within a river basin results in varying impacts to hydrology and material transport. Due to the dynamic nature of coastal waters, the monitoring of material transport solely by using traditional field measurements proves difficult over large areas and especially during and following storm events where the collection of field samples is often not possible. To offset this limitation, an integrated method incorporating field sampling, numerical modeling, and remote sensing was used to monitor the transport and distribution of terrestrially derived material from the Neuse River basin to the Neuse River and Neuse River Estuary (NRE) following Hurricane Irene in August 2011. Field samples were used to quantitatively characterize changes in the concentration of total suspended matter (TSM), colored dissolved organic matter (CDOM), dissolved organic carbon (DOC) and salinity in the Neuse River and NRE; numerical modeling was used to simulate the transport and distribution of freshwater and DOC throughout the NRE; and remote sensing was used to provide unique large-scale synoptic views of suspended sediment following the storm. This integrated method was adequate in providing the spatial and temporal resolution needed to examine the land-water processes that govern the transport of material through this coupled land-estuary system. This methodology may be applicable to similar estuarine systems and can help better characterize flow and transport during and following storm events.