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projects > freshwater flows into northeastern florida bay > abstract
Quantity, Timing, and Distribution of Freshwater Flows into Northeastern Florida BayA major Everglades restoration goal is to provide the wetland and Florida Bay with the right amount of water at the right time. The need for accurate information on the quantity, timing, and distribution of water flows through the Everglades into Florida Bay is essential for successful water management as it relates to restoration efforts. Accurate flow information is needed to help understand and simulate circulation, mixing, and salinity dynamics in Florida Bay as well as to help verify terrestrial simulations of south Florida marsh-flow dynamics. Such simulations are, in turn, used to drive projections of ecosystem changes in response to restoration alternatives. Also, with this flow information, water management practices can be monitored and informed decisions can be made to help restore the Everglades.
The quantity of water flowing through Taylor Slough and the C-111 Basin, including rainfall and evaporative losses, can be defined as total cumulative outflow volume in acre-feet from the creeks. The USGS water year (October through September) annual summaries for 1996-99 of outflow volume for the five instrumented and four noninstrumented sites are presented in table 1. Sheetflow into northeastern Florida Bay is considered negligible because flow is channeled through a low lying ridge along the northeastern shore of the bay.
The timing of flows is directly related to the wet/dry season variations with more than 80 percent of annual freshwater flow entering northeastern Florida Bay between June and November. Negative flows predominate the dry season and lower water levels in the wetland along with southerly winds cause saltwater to intrude upstream and into the coastal sub-embayments, such as Joe Bay and upstream Taylor River. Due to the complex drainage basin of the southeastern Everglades and the flat topography, small changes in water level can cause changes in flow distribution that would not be observed without directly computing discharge at the creeks. Discharge computation and salinity observations at the creeks and sub-embayments have led to the following flow distribution interpretations: (1) Trout Creek carries approximately 50 percent of the freshwater outflow to northeastern Florida Bay including the gaged and ungaged creeks; (2) West Highway Creek rarely has net negative flow on a monthly basis; (3) McCormick Creek had net negative flow for water year 1998 following the El Nino event; (4) flow exchange between Joe Bay and Long Sound does occur, and direction of flow is dependent upon water levels in the Taylor Slough and C-111 Basins; and (5) northeastern Joe Bay shows a direct connection with outflows from S-18C.
(This abstract was taken from the Greater Everglades Ecosystem Restoration (GEER) Open File Report (PDF, 8.7 MB))
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U.S. Department of the Interior, U.S. Geological Survey, Center for Coastal Geology This page is: http://sofia.usgs.gov /projects/freshwtr_flow/qntytimabgeer00.html Comments and suggestions? Contact: Heather Henkel - Webmaster Last updated: 11 October, 2002 @ 09:29 PM (KP) |