Paraná River Delta 2013 flood as seen by AMSR-2, SMOS, Aquarius and and SAR systems
Poster- 13Th Specialist Meeting microwave Radiometry and Remote Sensing of The Environment – MICRORAD 2014 Pasadena, California – USA – March 24-27 de 2014
Abstract: Over the past decade, several flood monitoring/forecasting methodologies based on remote sensing data have been proposed. Among them, the ones based on microwave observations are the most successful, since large flood events and intense cloud covers are often encountered simultaneously. This is a severe limitation of flood monitoring based on optical instruments. In general, flooding increases the moisture of the soil and decreases its roughness. For higher water levels and in presence of vegetation cover, flooding also reduces the height of the emerged vegetation. In extreme cases, water level submerges vegetation. All these processes produce a decrease of the surface emissivity and an increase of the difference between the emissivity measured in the vertical and horizontal polarizations. Therefore, passive microwave polarization index (PI) has the potential to detect the fraction of inundated area and to monitor the increase of water level. These issues have been discussed in several papers (Prigent et al., 2007, Sippel et al 1994, Salvia et al., 2011). Furthermore, the backscattering coefficient is also sensitive to flooding and vegetation condition. In summary, the combination of microwave remote sensing (active and passive) constitutes a good option, in which the best of both systems (high spatial resolution from SAR and high temporal resolution from passive systems) can be exploited for large river basins monitoring. This led us to the development of a methodology to retrieve flooded area in herbaceous wetlands, based on active/passive microwave data (Salvia et al., 2011).