InSAR-based hydrology of the Everglades, South Florida
Shimon Wdowinski(1) and Richard Carande(2)
University of Miami,
Rosenstiel School of Marine and Atmospheric Science,
Miami, FL 33149-1098,
(2) Vexcel Corporation, 4909 Nautilus Court, Boulder CO 80301, United States
The Everglades region in south Florida is a unique ecological
environment. Anthropogenic changes in the past 50 years, mainly for
water supply, agricultural development and flood control purposes, have
disrupted natural water flow and severely impacted the regional
ecosystem. Currently, Evergladesí flow is controlled by a series of
structures (e.g., levies, gates), which provide a large-scale natural
laboratory for monitoring and modeling wetland surface flow.
Evergladesí water level is currently monitored by about 100 stations,
about half of which provide real-time data.
We use space-based Interferometric Synthetic Aperture Radar (InSAR) to
monitor water level variations in the entire Everglades region with a
high spatial resolution (~30 x 30 m2). Our data consists of three
225x75 km2 swaths of eastern South Florida, acquired in June, August
and December 1994 by the L-band (1.275 GHz) JERS satellite. A
comparison between the space-based InSAR observations and 20 ground-
truth stage station data points shows a remarkable agreement. The most
significant water level changes are obtained in the northern section of
the study area, known as Water Conservation Areas (WCA) 1, 2A, and 2B.
Our results show dynamic water topography caused by gate operation on
man-made levees. The data show up to 1 m of elevation difference across
5-15 km length scale. We detected both regional N-S unidirectional and
radial topography patterns.
We model the dynamic water topography using 1-D unidirectional and
radial diffusion flow models. Our models allow us to determine a
regional-scale flow conductivity parameter, which reflects the
resistance to water flow due to vegetation. Future 2-D numerical flow
models will enable us to determine local variations of the conductivity
parameter as well as better tools for modeling and managing surface
flow in the Everglades.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,