Long-Term Data from the USGS/BRD Mangrove Hydrology Sampling Network in Everglades
National Park.
Gordon H. Anderson
U.S. Geological Survey, Center for Water & Restoration Studies, Homestead, FL
Thomas J. Smith III
U.S. Geological Survey, Center for Water & Restoration Studies, St. Petersburg, FL
In 1992, under the guidance and support of the USGS Global Change Research
Program (GCRP), The “Groundwater-surface water interactions and sea-level rise in
southern Florida study” was initiated. The principle focus of the study was to develop a
systematic network of shallow groundwater well and surface water monitoring sites to
evaluate the hydrodynamic changes across the transition zone or ecotone between the
freshwater Everglades and coastal mangrove estuaries. Located on the southwestern
coast of Florida, within Everglades National Park, transects were established along the
three principal tidal rivers: Shark, Lostman, and Chatham River (Fig. 1). Shark River
slough and its estuary were selected as the primary study area, because of their
significance to the freshwater Everglades system. Each transect is ~30 km in length (the
meso-scale) and has three permanent, continuously recording hydrologic monitoring
stations. On the Shark River transect, Shark 1 (SH1) represents the upland non-tidal
freshwater region; Shark 2 (SH2), the transitional ecotonal area between the two
hydrologic systems; and Shark 3 (SH3) the coastal mangrove estuary region. Two
additional hydrology stations (SH4 and SH5) were set up to monitor hydrologic
changes across the fringe mangrove/coastal marsh ectone ~ 300m in length (the microscale). Shallow ground and surface water levels, temperature and specific conductance,
and rainfall are the principal parameters measured at each monitoring site.
Hydrologic data from the Shark River Transect has been compiled for seven water
years: 1996-2002 (Fig. 2). Daily surface water from SH1 shows the wet tropical
summer (June-October) weather and drier cooler winter (November-May) climate
patterns of south Florida. The non-tidal, freshwater marshes respond quickly to local
rainfall and evaporation, surface-water discharge from upstream. Water levels in Shark
Slough were significantly higher in 1995 and 1999. Hurricane Irene in October 1999
was the largest single event recorded at SH1 since 1995. SH2 is located on the terminus
of the freshwater slough, at the ecotone with downstream tidal systems. Principally,
SH2 showed a tidal signal in the daily surface water, however, it was dampened by the
overland flow of surface water during the summer months, primarily June and in
September. Tropical storm Harvey in September 1999 was the largest single event
recorded at SH2 since 1995. SH3 is located on a red mangrove delta island near the
mouth of the Shark River estuary. It is overwhelmingly a tidally influenced site,
receiving a tidal influx twice daily. Tropical Storm Harvey in September 1995 was the
single largest event recorded at SH3 since 1995.
The project is developing a common vertical reference for the southwest coast to
provide greater comparative analysis of hydrologic data (DeWitt et al., this volume).
The Shark River hydrologic network is centrally positioned to provide essential
baseline empirical physical data needed for numerous research efforts and modeling
involved with Everglades restoration. Such projects include the Tides and Inflows in
the Mangroves of the Everglades (TIME) and a variety of inter-related USGS
hydrological, ecological, geological and mapping investigative studies. These data
provide valuable integration with South Florida National Parks resource management;
the Comprehensive Everglades Restoration Plan (CERP); and the Florida Coastal Long
Term Ecological Research (LTER) project.
Figure 1. Locations of hydrologic sampling sites within Everglades National Park.
Figure 2. Period of record for surface water stage along the main Shark River transect.
Contact: Gordon H. Anderson, U.S. Geological Survey, Everglades Field Station, c/o
Beard Center, Everglades National Park, 40001 State Road 9336, Homestead, FL
33034, Phone: 305-242-7891; FAX 305-242-7836; Email: gordon_anderson@usgs.gov
Poster, Hydrology & Hydrological Modeling