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Title
Remote sensing for resources development and environmental management
Author
Damen, M. C. J.

foreshortening as well as foldover, in some
cases, even make topography effects more
dramatic.
4 DATA INTERPRETATION
Data sets over both test area were
interpreted visually. A series a schematic
diagram has been drawn (Figures 2 and 3).
4.1 The island of La Gonave
The island of La Gonave can be described as
an anticline oriented WNW-ESE (Butterlin,
1960). Several domes (locally named "morne"
are observed on the coregistered data set
(Mercier de l'Epinay et al. 1985), they are
(from NW to SE):
the Morne Dandeville which affects some
Miocene sandstones. It is well seen on
the Seasat image because some stratas are
perpendicularly oriented to the Seasat
radar illumination direction,
the domes of Plaisance and
Morne-La-Pierre (Eocene of age) are
observed on both Landsat MSS and Seasat
data. An ambiguity exists in detecting
the Morne-La-Pierre since its topography
is not very well expressed,
the dome of Pointe Fantasque is very well
detected and may only be the southern end
of the anticline.
Three fault zones can be recognized:
group 1: N65° to N70°. They are 10 to
15 Km long and are well detected on the
MSS images. Some faults oriented NW-SE
delimit diamond shape areas where recent
alluvial deposits can be found,
group 2: subparallel to the anticline
axis, they affect terrains Miocene of
age. They are more numerous close to the
center of the anticline. Their
orientation indicates a gentle bending of
the axis of the anticline,
group 3: N80° to N95° which crosses all
the structures previously described.
The island of La Gonave may be interpreted
as a broad folding structure related to the
left lateral shear of South-Haiti as defined
by Calmus, 1984. The signification of the
domes of Dandeville, Plaisance and
Morne-La-Pierre is still not explained and
may be related to some evaporite extrusions
(Mercier de l'Epinay et al. 1985).
possible to locate major faults related to
the left lateral shear of South-Haiti.
Drainage pattern are detected on both data
sets but distorsion are less important on the
SIR-B data. Basaltic rocks are easier to
locate on the Seasat SAR image.
5 SUMMARY
Synthetic Aperture Radar data obtained by
Seasat in 1978 and by SIR-B in 1984 were
compared over the Western part of Haiti. Two
areas were studied : the island of La Gonave
and the Miragoane area. Boundaries between
rocks Eocene of age and rough basalts were
precised as well as 1) domes, 2) ancients
faults oriented NE-SW, 3) faults oriented
NW-SE linked to the La Gonave anticline and
4) faults oriented E-W integrated in the
tectonic model of the Caribbean plate.
REFERENCES
Butterlin, J. 1960. Géologie générale et
régionale de la République d'Haiti. Trav.
et Mém. de l'Institut des Hautes Etudes
d'Amérique Latine. Vol. VI, 194 p.,
Paris.
Calmus T. 1984. Décrochement senestre
Sud-Haitien: analyse et conséquences
paléogéographiques dans la région de
Camp-Perrin (Massif de Macaya, prequ'île du
Sud d'Haiti). Ann. Soc. Géol. Nord, t C
III, p.309-316.
Ford, J.P., J. B. Cimino, B. Holt and M.
R. Ruzek 1986. Shuttle imaging radar
views the earth from Challenger: the SIR-B
experiment. JPL publication 86-20.
Mercier de l'Epinay, B., Ph. Rebillard, J.
Chorowicz, P. Letouzey and J.M. Vila
1985. Interprétation structurale de l'île
de La Gonave (République d'Haiti) à partir
d'images spatiales Landsat-MSS et Seasat
SAR 1985. Géodynamique des Caraibes symp.,
p.363-369, Technip editon.
Rebillard, Ph. and D. Evans 1983. Analysis
of coregistered Landsat, Seasat and SIR-A
images of varied terrain types. Geophys.
Res. Letters 10-4, p.277-280.
Vila, J.M., J. Butterlin, T. Calmus, B.
Mercier de l'Epinay and B. Van Den Berghe
1983. Atlas d'Haiti (Ch. Girault ed.),
CEGET/CNRS Bordeaux.
4.2 The Miragoane area
The interpretation map of figure 4 was drawn
using the map published by Vila and al.,
1983.
Both Seasat SAR and SIR-B were acquired with
almost the same radar illumination direction
(therefore the layover is toward the West).
The 20° incidence angle of Seasat, as
mentionned earlier, induces foreshortening
and foldover which impair greatly the
interpretation. In mountaineous terrain,
larger incidence angle such as the one of
SIR-B over Haiti (60°), improves the
interpretation ability. But on the other
hand, the poor SIR-B signal to noise reatio
did not enable to get a perfect radar image.
Nevertheless, from both data set it is
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