Mangrove vegetation structure in Southeast Brazil from phased array L-band synthetic aperture radar data

Francisca Rocha De Souza Pereira,Milton Kampel,Marilia Cunha-Lignon

doi:10.1117/1.jrs.10.036021

Abstract

The potential use of phased array type L-band synthetic aperture radar (PALSAR) data for discriminating distinct physiographic mangrove types with different forest structure developments in a subtropical mangrove forest located in Cananeia on the Southern coast of Sao Paulo, Brazil, is investigated. The basin and fringe physiographic types and the structural development of mangrove vegetation were identified with the application of the Kruskal–Wallis statistical test to the SAR backscatter values of 10 incoherent attributes. The best results to separate basin to fringe types were obtained using copolarized HH, cross-polarized HV, and the biomass index (BMI). Mangrove structural parameters were also estimated using multiple linear regressions. BMI and canopy structure index were used as explanatory variables for canopy height, mean height, and mean diameter at breast height regression models, with significant R 2 =0.69 , 0.73, and 0.67, respectively. The current study indicates that SAR L-band images can be used as a tool to discriminate physiographic types and to characterize mangrove forests. The results are relevant considering the crescent availability of freely distributed SAR images that can be more utilized for analysis, monitoring, and conservation of the mangrove ecosystem.

Highlights

In tropical and subtropical regions, disordered urban occupancy and land use of coastal zones have caused the degradation of typical ecosystems like mangroves
Considering the relative scarcity of synthetic aperture radar (SAR) studies that investigate the structural characteristics of basin and fringe mangroves, the present study aims to evaluate the use of advanced land observing satellite (ALOS) phased array type L-band SAR (PALSAR) data for discriminating distinct physiographic mangrove types with different forest structure developments in a subtropical mangrove forest located in Cananéia on the southern coast of São Paulo, Brazil
This work indicates that an L-band SAR image acquired in conditions of high tide, with an incidence angle of 25.7 deg allows the identification of different physiographic types and structural developments of mangrove forests

Summary

Introduction

In tropical and subtropical regions, disordered urban occupancy and land use of coastal zones have caused the degradation of typical ecosystems like mangroves. The development of a mangrove’s forest structure is associated with the intensity and frequency of environmental factors.[5,6] Generally, the maximum structural development of mangrove forests occurs in regions where appropriate topography is subject to large tidal range, ample freshwater input, precipitation, nutrients, and sediments.[5,6] A classification of mangroves based on physiographic and structural attributes was first presented by Lugo and Snedaker.[7] Schaeffer-Novelli et al.[8] suggested a classification in two main types, according to their physiographic characteristics: fringe and basin forests This classification approach is more related to Journal of Applied Remote Sensing

Results

Discussion

Conclusion