The Use of Multipolarized Spaceborne SAR Backscatter for Monitoring the Health of a Degraded Mangrove Forest

• Published in: Journal of coastal research Vol. 24; no. 1; pp. 248 - 254
• Main Authors: Kovacs, John M., Vandenberg, Casey V., Wang, Jinfei, Flores-Verdugo, Francisco
• Format: Journal Article
• Language: English
• Published: Fort Lauderdale Coastal Education and Research Foundation (CERF) 01.01.2008; Allen Press Inc
• Subjects: Backscattering; Brackish; Coastal ecology; Coefficients; Data collection; ENVISAT; Floods; Forest canopy; Forest ecology; forested wetland; Forestry research; Forests; Laguncularia racemosa; Leaf area index; leaf area index (LAI); Leaves; Mangrove forests; Mexico; Radar; Remote sensing; RESEARCH PAPERS; Satellites; Studies
• ISSN: 0749-0208; 1551-5036
• DOI: 10.2112/06-0660.1

To determine whether multipolarized spaceborne synthetic aperture radar could be used to monitor the health of a mangrove forest, leaf area index, as well as other biophysical parameter data, from stands dominated by white mangrove (Laguncularia racemosa) and located within a degraded mangrove forest were examined in relation to backscatter coefficients from ENVISAT synthetic aperture radar scenes. The results indicate that polarization and, to a lesser extent, incident angle play a significant role in the ability to estimate both leaf area index and mean tree height. No significant linear coefficients of determination were observed between the recorded parameters and the backscatter coefficient from any of the copolarized scenes. With regards to leaf area index, r2 values of 0.82 and 0.73 were calculated for the cross-polarized data at two incident angles. For mean tree height, the linear coefficient of determination was much higher for the smaller incident angle data than for the larger incident angle data. No significant relationships were identified for stem density, basal area, or mean diameter at breast height. It is postulated that the inability of the copolarized ENVISAT advanced synthetic aperture radar data to differentiate between dead mangrove stands and healthy ones is the result of equally high backscatter resulting from strong scattering from trunk–ground double bounce and crown volume, respectively.