Temporal changes of mangroves vegetation boundaries in Amazonia: application of GIS and remote sensing techniques

COHEN, MARCELO; LARA, RUBÉN JOSÉ

WETLANDS ECOLOGY AND MANAGEMENT

Springer

Lugar: Amsterdam; Año: 2003 p. 223 - 231

0923-4861

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0pt; margin-bottom:.0001pt; mso-pagination:none; text-autospace:none; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES-TRAD; mso-fareast-language:ES;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> <!-- /* Font Definitions */ @font-face {font-family:Times; panose-1:2 2 6 3 5 4 5 2 3 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0pt; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; mso-bidi-font-size:10.0pt; font-family:Times; mso-fareast-font-family:Times; mso-bidi-font-family:"Times New Roman"; mso-ansi-language:EN-GB; mso-fareast-language:PT-BR;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> The present work analyses a 25-year time series of radar and satellite images, and identifies areas with losses and gains of vegetation coverage along ~166 km of Para’s coastline (North Brazil) and in the inner parts of the Bragança peninsula. The geomorphology of this region has significantly changed in recent years. A result of these changes has been a retreat of the mangrove vegetation along the coastline, mainly due to landward sand migration, which covers the mudflat and asphyxiates the vegetation. Image analysis suggests that the loss of vegetation coverage has been the dominating process in the last 25 years, occurring on ~42% of the Bragança coastline and adjacent areas. Vegetation has remained stable along ~39% of the coastline, while mud sedimentation has allowed mangrove development along ~19% of it. On the other hand, during this period of time, mangroves have invaded 3.4 km2 (~38%) of the elevated herbaceous flats in the highest sectors of the Bragança peninsula. Despite other possible causes for mangrove death along the coastline, such as littoral drift currents or cyclical changes in coastal sediment dynamics, the invasion of mangrove into herbaceous elevated flats in the central peninsula cannot be attributed to these factors. The current dynamics of vegetation coverage change seem to be compatible with a long-term trend related to the predicted rates of sea-level rise