INCORPORATION OF CONTINENTAL AND URBAN RUN-OFF INTO A COASTAL CIRCULATION MODEL: APPLICATION TO THE CATALAN COAST

Maria Liste, Manel Grifoll, Ingrid Keupers, Jaak Monbaliu, Manuel Espino

Abstract


A 3D hydrodynamical model has been set up to incorporate the continental and urban run-off into the Catalan Coastal waters. Particular attention was paid to introducing correctly the freshwater plumes and attention was also paid to determinate the influence of the land discharge profile with regard to the distributed continental run-off. The model domain includes a small part of the Catalan Coast where the combination of local land topography with torrential rainfall caused considerable local runoff on a short period of time with a large impact on the receiving coastal waters.
The Regional Ocean Modeling System (ROMS) simulations were used to examine the dispersal to a freshwater delivery from two relevant event; a low river discharge typical of mean conditions during April 2011 and a high discharge representative of the storm event during March 2011 are considered. We have observed the plume responses to an abrupt change in river discharge. During the mean conditions, low salinity water is concentrated around the rivers mouth while during the flood event, the plume spread offshore in the direction of river water outflow and turned downstream close to the coast. The differences between a simulation including the river outflow as a land forcing and a simulation including river and urban runoff as a land forcing suggested that the urban runoff plays an important role in the spreading and shape of the river plume.

Keywords


land boundary fluxes; urban runoff; river discharge; freshwater plume

References


Avicola, G., and P. Huq . (2003a). The characteristics of the recirculating bulge region in coastal buoyant outflows. J. Mar. Res, 61, 435–463.http://dx.doi.org/10.1357/002224003322384889

Avicola, G., and P. Huq. (2003b). The role of outflow geometry in the formation of the recirculating bulge region in coastal buoyant outflows. J. Mar. Res, 61, 411-434.http://dx.doi.org/10.1357/002224003322384870

Bourrin, F., P. L. Friend, C. L. Amos, E. Manca, C. Ulses, A. Palanques, and X. Durrieu de. (2008). Sediment dispersal from a typical Mediterranean flood: The Têt River, Gulf of Lions. Continental Shelf Research, 28(15), 1895-1910.http://dx.doi.org/10.1016/j.csr.2008.06.005

Choi B.J. and J.L. Wilkin. (2007). The Effect of Wind on the Dispersal of the Hudson River Plume. Journal of Physical Oceanography, 37, 1878-1897.http://dx.doi.org/10.1175/JPO3081.1

Fong D. A., and W.R. Geyer. (2001). Response of a river plume during an upwelling favorable wind event. J. Geophys. Res, 106, 1067–1084.http://dx.doi.org/10.1029/2000JC900134

Fong, D., and W. Geyer. (2002). The alongshore transport of freshwater in a surface‐trapped river plume. J. Phys. Oceanogr, 32, 957–972.2.0.CO;2">http://dx.doi.org/10.1175/1520-0485(2002)032<0957:TATOFI>2.0.CO;2

Nof, D., and T. Pichevin. (2001). The ballooning of outflows. J. Phys. Oceanogr, 31, 3045–3058.2.0.CO;2">http://dx.doi.org/10.1175/1520-0485(2001)031<3045:TBOO>2.0.CO;2

Schiller R.V., V.H. Kourafalou, P. Hogan, and N.D. Walker. (2011). The dynamics of the Mississippi River plume: Impact of topography, wind and offshore forcing on the fate of plume waters. Journal of Geophysical Research, 116, C06029.http://dx.doi.org/10.1029/2010JC006883

Shchepetkin J.C., and A.F. McWilliams. (2005). The Regional Ocean Modeling System (ROMS): A split-explicit, free-surface, topography-following coordinates ocean model. Ocean Modelling, 9, 347-404.http://dx.doi.org/10.1016/j.ocemod.2004.08.002

Shchepetkin, A.F., and J.C. McWilliams. (2009). Correction and commentary for ''Ocean forecasting in terrain-following coordinates: Formulation and skill assessment of the regional ocean modeling system" by Haidvogel et al., J. Comp. Phys. Journal of Computational Physics, 228, 3595–3624.

Wang Y., Z. Liu, H. Gao, L. Ju, and X. Guo. (2011). Response of salinity distribution around theYellow River mouth to abrupt changes in river discharge. Continental Shelf Research, 31, 685–694.http://dx.doi.org/10.1016/j.csr.2011.01.005

Warner J.C., W.R. Geyer, and J.A. Lerczak. (2005). Numerical modeling of an estuary: A comprehensive skill assessment 2005 Journal of Geophysical Research. Journal of Geophysical Research, 110, C05001.

Whitney M.M. and R.W. Garvine. (2005). Wind influence on a coastal buoyant outflow. Journal of Geophysical Research, 110, C03014.http://dx.doi.org/10.1029/2003JC002261

Xia M., L. Xie, and L.J. Pietrafesa. (2010). Winds and the orientation of a coastal plane estuary plume. Geophysical Research Letters, 37, L19601.http://dx.doi.org/10.1029/2010GL044494

Zhang W.G., J.L. Wilkin, and R.J. Chant. (2009). Modeling the Pathways and Mean Dynamics of River Plume Dispersal in the New York Bight. Journal of Physical Oceanography, 39, 1167-1183.http://dx.doi.org/10.1175/2008JPO4082.1


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