Assessment of fire peatland damages using polarimetric L-band ALOS

The potential of polarimetric L-band PALSAR and the Touzi decomposition [1] for peatland classification and mapping is confirmed using a series of polarimetric ALOS acquisitions collected in the Athabasca oil sand exploration region (near Fort McMurray, Alberta). The sensitivity of the scattering type phase to peatland subsurface water flow permits an enhanced discrimination of poor fen from bogs; two wetland classes that can hardly be discriminated by optic and conventional SAR sensors. The complementary information provided by the new “scattered wave” polarization signature [2] and its optimization, is also confirmed. The extrema of the degree of polarization (DoP) permit accurate assessment of peat health in burned treed bogs. The dynamic range (dRo) of the total scattered wave intensity permits better discrimination of burned from healthy forests in comparison with the intensity parameters generated with the incoherent target scattering decomposition (ICTD) and the conventional multi-polarization channels (HH, HV and VV). The added value of polarimetric L-band SAR information to Optics (Landsat TM) sensors for assessment of fire damages over peatlands is well demonstrated. While optics sensors can identify well burned forest and peatlands areas, accurate assessment of peat health in burned treed bogs can only be obtained using the peat subsurface information provided by the long penetrating L-band polarimetric ALOS.