INTER-ANNUAL VARIABILITY IN NET OUTFLOW FROM INDIAN RIVER LAGOON

• Published in: Florida scientist Vol. 70; no. 4; pp. 332 - 343
• Main Author: Smith, Ned P.
• Format: Journal Article
• Language: English
• Published: Orlando The Florida Academy of Sciences, Inc 01.10.2007; Florida Academy of Sciences, Inc
• Subjects: Annual variations; Canals; Estuaries; Fresh water; Inlets; Lagoons; River water; Sea level; Sea water; Surface runoff; Water outflow; Wind; USA, Florida, Indian River Lagoon; ASW, USA, Florida, Indian River Lagoon; ASW, USA, Florida, Mosquito Lagoon; A, Atlantic; USA, Florida, Mosquito Lagoon
• ISSN: 0098-4590
• DOI: 10.1043/0098-4590(2007)70[332:IVINOF]2.0.CO;2

A hydrodynamic model is used to simulate exchanges between Indian River Lagoon and Atlantic shelf waters, and between Indian River Lagoon and Mosquito Lagoon, during the four-year period from 1993 to 1996. Exchanges are in response to wind stress forcing, tidal and nontidal variations in shelf water level and freshwater outflow from 16 drainage canals. Wind forcing is similar from one year to the next, but the timing and magnitude of freshwater releases vary considerably. St. Lucie Inlet is highly responsive to the magnitude of freshwater runoff, most of which arrives through the St. Lucie Estuary. When low discharge into the St. Lucie Estuary coincides with northward wind forcing, a nontidal inflow through St. Lucie Inlet can persist for several weeks to several months. At times of high discharge into the St. Lucie Estuary, most of the outflow occurs through St. Lucie Inlet, but outflow through Ft. Pierce Inlet increases as well. In three of the four years of the study, outflow is greatest through Ft. Pierce Inlet. Model results for all four years suggest a net outflow through Haulover Canal that is of the same order of magnitude as the outflow through the three inlets.