The Geomorphological Settings of the Amazon Muddy Coastal Zone:

an overview from remote sensing and field ancillary data

Pedro Walfir M. Souza FilhoUniversidade Federal do Pará, Centro de Geociências

Centro de GeociênciasLaboratório de Análise de Imagens do Trópico Úmido

Geologic approach

Tectonic, physiographic, geomorphologic, sedimentologic, climatic and oceanographic information from the Amazon coastal zone were reviewed focusing on the factors leading to recognize different geomorphological settings of the Amazon coastal zone

PhysiographicPhysiographic aspects aspects

Low reliefLow reliefWide coastal Wide coastal plain and plain and continental continental shelfshelfHigh drainage High drainage densitydensity

© 2000 USGS

The control of structural framework on coastal The control of structural framework on coastal geomorphological settinggeomorphological setting

Morphostructural settings:

-Guyana coast

-Amapá coast

-Marajó island

- Pará/ Maranhão coast

Gorini & Brian, 1976

Sedimentary environments:coastal zone and continental shelf

Geomorphological Settings of the Amazon Muddy Coastal Zone

Souza Filho & Prost, 2002

Sector I: Guyana Coast - Muddy CapesSector I: Guyana Coast - Muddy CapesGeomorphological Investigation from ERS-1Geomorphological Investigation from ERS-1

Erosional Interbank and Depositional Erosional Interbank and Depositional

Mud Bank Zone in French GuianaMud Bank Zone in French Guiana

KourouCSG

Salut Islands

N

ERS-1 image © European Space Agency, 1992ERS-1 image © European Space Agency, 1992

Avicennia sp.

Mangrove

Mud Banks

Erosional Interbank

Depositional Mud Bank

Sector I: Amapá Coast Sector I: Amapá Coast Muddy Capes and Muddy Capes and Fringed MangrovesFringed Mangroves

Cunani Estuarine Mouth - AmapáCunani Estuarine Mouth - Amapá

ERS-1 image © ESA, March 16. 1992ERS-1 image © ESA, March 16. 1992

Mud bank

Beach ridge

Marsh

Marsh

Beach ridgeMud bank

N

Orange and Cassiporé capes - AmapáOrange and Cassiporé capes - Amapá

JERS-1 image © NASDA, Oct 31. 1996JERS-1 image © NASDA, Oct 31. 1996

Sector II: Lake region and Marajó IslandSector II: Lake region and Marajó IslandWet grasslandWet grassland

Franco Island, Gurijuba Channel- AmapáFranco Island, Gurijuba Channel- Amapá

ERS-1 image © ESA, 1992ERS-1 image © ESA, 1992

Emerged mud banks

Submerged mud banks

Grassland

Emerged mud bank

Grassland

Gurijuba channel

Franco Island

N

Lakes region - AmapáLakes region - AmapáJERS-1 image © NASDA, Oct 31. 1996JERS-1 image © NASDA, Oct 31. 1996

Sector III: Marajó IslandSector III: Marajó IslandWet grasslandWet grassland

Wet-grass land - MarajóWet-grass land - MarajóJERS-1 image © NASDA, Oct 31. 1996JERS-1 image © NASDA, Oct 31. 1996

Sector IV: Pará - Maranhão CoastSector IV: Pará - Maranhão CoastMacrotidal MangroveMacrotidal Mangrove

N

ERS-1 image © ESA, 1992ERS-1 image © ESA, 1992

Northeastern Pará StateNortheastern Pará State

Coastal Plateau

Mangroves

Savannah

Dune-Beach ridgeEbb-tidal delta

Muddy Coast:Muddy Coast:processes in different spatial scaleprocesses in different spatial scale

Mangrove coast

7.800 km2Souza Filho & Lara, in press

Geomorfological Investigation Based on Geomorfological Investigation Based on RADARSAT and Landsat TM Integrated ProductRADARSAT and Landsat TM Integrated ProductBragança Mangrove Coast - ParáBragança Mangrove Coast - Pará Coastal Features

a = intertidal mangrovesb = supratidal mangrovec = deforested mangroved = regenerated mangrovee = inner salt marsh f = outer salt marshg = chenier sand ridgeh = barrier-dune beach ridge,i = ebb-tidal deltaj = tidal sandflatk = submerse sandy bankl = tidal estuarine channel

82% muddy environments

Geomorfological Investigation...Geomorfological Investigation...

Geomorphological Map Geomorphological Map from SPC-SAR Integrated Productfrom SPC-SAR Integrated Product

Different muddy coastal sedimentary environments

Muddy Coast:Muddy Coast:processes in different time scaleprocesses in different time scale

Stratigraphic evolution of the Bragança Coastal Plain

What happened 2,100 years ago? Sandy coast Muddy coast

Medium-Term Shoreline Changes from Airborne (GEMS, Medium-Term Shoreline Changes from Airborne (GEMS, 1972) and Spaceborne (RADARSAT, 1998) SAR1972) and Spaceborne (RADARSAT, 1998) SAR

10 kmA

B

C

RADARSAT image: 1998 GEMS 1000 vector: 1972

Shoreline change: A = -1.500; B = -1.250; C = +1.250 28m

Medium-Term Shoreline Changes...Medium-Term Shoreline Changes...

Erosive shorelineErosive shoreline Progradational shorelineProgradational shoreline

RADARSAT image © Canadian Space Agency, 1998RADARSAT image © Canadian Space Agency, 1998

Shoreline change evaluation (1972 - 1998)Shoreline change evaluation (1972 - 1998)

Which are the main processes that control erosion/accretion along the time?

Shallow Water Morphology and Coastal Shallow Water Morphology and Coastal Processes from RADARSAT-1.Processes from RADARSAT-1.

RADARSAT image © Canadian Space Agency, 1998RADARSAT image © Canadian Space Agency, 1998

Summary of Coastal Studies on Amazon RegionSummary of Coastal Studies on Amazon Region

Distinct remote sensing systems with different configurations have provided high quality data for muddy coastal features identification in wet tropical environments.

The effective applicability of the remote sensing technology depends on the understanding of radar and optical RS fundamentals, digital image processing, field investigations and the knowledge about the discipline vs. application involved.

SAR data will provide to geoscientist a powerful terrain visualization of the coastal geomorphological units, which can not be acquired from field observations alone.

This lecture has shown the importance of using remote sensing as a fundamental tool for mapping and monitoring purposes in moist tropical coastal environments of the Amazon region.

Geomorphologic, stratigraphic and oceanographic processes must be understood on different time and spatial scale. How we can do this?

The great objective of many generations is:

Try to understand what is going on Amazon muddy coast?