Abstract:

The work discussed in this paper involves the analysis of the data obtained by two sensors LANDSAT/TM and SAR ERS-1 separately and in combination, to determine the synergistic effects in the study of the Parana's delta, a freshwater wetland in Argentina. The Lower Delta hydrology of Parana's river is dominated mainly by the Parana's river and De La Plata river estuary. The flooding patterns, the hydrologic regime, the geomorphologycal changes in the islands from upstream to downstream and the patterns of human activity determine the characteristics of this large wetland. This work is part of an ESA/CONICET (Satellite Radiometry Group) pilot project entitled "Integrated study of the Argentine Coastal Environments". This group received four ERS-1 images from this area, corresponding to August 1995 (winter season in the southern hemisphere). Due to date limitations of ERS-1/SAR images and to the delta's landscape complexity for microwave analysis, a test area was chosen. A complete study of the area was undertaken prior to this work using a multitemporal series of TM data (to take into account the phenology cycle of vegetation), aerial photography and field work. An habitats conceptual classification scheme was also developed. Therefore, the purpose of this work was to evaluate the following topics: highland and lowland species distribution, batimetric relief, forest management, etc, where optical and radar data used in combination could provide a better understanding and discrimination of natural habitats, forest plantations, and water patterns. This paper describes the preprocessing steps applied to TM data and ERS-1 data. Next, the effect of the environment (wind) on the radar images and the analysis techniques used. This is followed by a discussion of the synergic effects on land and water. A discussion of the problems that arise when only one of the required dates (vegetation phenology cycle) are available and when the images differ in the hydrologic conditions follows.. Recommendations for the continuation of this work are included in the conclusions.