Using JERS-1 L-band SAR to estimate methane emissions from the Jau/spl acute/ river floodplain (Amazon/Brazil)

• Main Authors: Rosenqvist, A., Forsberg, B.R., Pimentel, T., Richey, J.E.
• Format: Conference Proceeding
• Language: English
• Subjects: Floods; Gases; L-band; Marine animals; Production; Rain; Rivers; Satellites; Sea measurements; Terrestrial atmosphere
• DOI: 10.1109/IGARSS.1998.691651

Demonstrates how multi-temporal JERS-1 L/sub HH/ band SAR data can be used to derive detailed spatial and temporal information about wetland distributions and improve estimates of methane fluxes from these environments. Within the framework of the NASDA-led Global Rain Forest Mapping (GRFM) project, a part of the Jau/spl acute/ river in the central part of the Amazon basin, was monitored during two full flooding cycles with JERS-1, and a spatial/temporal model of the inundation patterns along a 40-km long segment of the river was developed. Simultaneously with the SAR acquisitions, measurements of CH/sub 4/ emissions and flooding extent along a transect through the seasonally flooded forest in the Jau/spl acute/ were performed. The ground measurements verify a clear relationship between the L-band backscatter and the status of inundation. A simple CH/sub 4/ flux model was developed and in combination with the JERS-1 inundation model, daily CH/sub 4/ fluxes could be estimated. Early results confirm significant CH/sub 4/ emissions from floodplain environments, indicating amounts up to 2000-4000 tons/year from the 1000 km/sup 2/ test area, where some 200 km/sup 2/ correspond to seasonally flooded forest. CH/sub 4/ fluxes were found to vary significantly between years depending on the river level, with the maximum flooded area being a key control parameter. Model results suggest that about 75% of the yearly fluxes in the basin occur within a period of about three months, when the river levels are receding.