Modeling bed-load transport of coarse sediments in the Great Bay Estuary, New Hampshire

A. Bilgili*, M. R. Swift, D. R. Lynch, J. T.C. Ip

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


Current, sea level and bed-load transport are investigated in the Lower Piscataqua River section of the Great Bay Estuary, New Hampshire, USA - a well-mixed and geometrically complex system with low freshwater input, having main channel tidal currents ranging between 0.5 and 2 m s-1. Current and sea level forced by the M2M4M6 tides at the estuarine mouth are simulated by a vertically averaged, non-linear, time-stepping finite element model. The hydrodynamic model uses a fixed boundary computational domain and accounts for flooding-drying of tidal flats by making use of a groundwater component. Inertia terms are neglected in comparison with pressure gradient and bottom friction terms, which is consistent with the observed principal dynamic balance for this section of the system. The accuracy of hydrodynamic predictions in the study area is demonstrated by comparison with four tidal elevation stations and two cross-section averaged current measurements. Simulated current is then used to model bed-load transport in the vicinity of a rapidly growing shoal located in the main channel of the lower system. Consisting of coarse sand and gravel, the shoal must be dredged every five to eight years. Two approaches are taken - an Eulerian parametric method in which nodal bed-load flux vectors are averaged over the tidal cycle and a Lagrangian particle tracking approach in which a finite number of sediment particles are released and tracked. Both methods yield pathways and accumulations in agreement with the observed shoal formation and the long-term rate of sediment accumulation in the shoal area.

Original languageEnglish
Pages (from-to)937-950
Number of pages14
JournalEstuarine, Coastal and Shelf Science
Issue number4
Publication statusPublished - Dec 2003
Externally publishedYes


We thank Prof. Wendell Brown and Prof. Barbaros Çelikkol for many helpful suggestions, and Mr. Brian Blanton for his help in the particle tracking program setup. Field observations were obtained as part of the 1975 Great Bay Estuarine Field Program under the New Hampshire Sea Grant College Program and NOS. Financial support from the Cooperative Institute for Coastal and Estuarine Environmental Technology (CICEET), NOAA/UNH (grant numbers NA77OR0357, NA87OR0512, NA87OR338) is gratefully acknowledged.

FundersFunder number
Cooperative Institute for Coastal and Estuarine Environmental Technology
National Oceanic and Atmospheric Administration
University of New HampshireNA87OR0512, NA77OR0357, NA87OR338


    • Bedload
    • New Hampshire coast
    • Numerical model
    • Sand waves
    • Sediment transport
    • Tidal currents
    • Tidal estuaries
    • Vertically integrated


    Dive into the research topics of 'Modeling bed-load transport of coarse sediments in the Great Bay Estuary, New Hampshire'. Together they form a unique fingerprint.

    Cite this