USGS
Greece -
Marineris
sented on
research
ted in an
cribed on
ams. The
ectilinear
of Grand
in fronts.
in Valles
d (12 km
1e. Valles
2 various
esis and
le from
on of the
c degree
ulation of
ween the
will be
2. METHODOLOGY
First the study area and data are introduced. Then the
geomorphometric parameters used in landscape characterization
are explored. Then selected general geomorphometric
parameters (Evans, 1980) defined for every node of the DEM
are computed and the resulting statistics are used in an attempt
to characterize landscape. Then a comparison between the
computed geomorphometric parameters of the Valles Marineris
and Grand Canyon is performed.
2.4 Geomorphometric Parameters
The easiest way to visualize the geomorphometric signature and
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B4. Istanbul 2004
From the other hand, hypsometric integral (HI) was used in
classical conceptual geomorphic models of landscape evolution
(Luo, 1998). It should be noted that the styles of landscape
evolution depend critically on the timescales of the tectonic
processes in relation to the response time of the landscape and
classical conceptual models may be valid under specific
tectonic conditions (Kooi and Beaumont, 1996). Descriptive
statistics of the general geomorphometric attributes (Evans,
1980) like elevation, gradient etc, were used to characterize the
landscape either at local or even at planet scale (Mark, 1975).
These gttributes were also used in a pixel based unsupervised
classification procedure aiming to capture the geometric
signature of landforms (Pike, 1987). In a previous research
effort, mean elevation (H), mean gradient (G), hypsometric
integral (HI) and local relief (LR) that equals to the elevation
Figure 2. 3D visualization of the Grand Canyon. Draped topographic map on the Grand Canyon 1-
degree DEM.
the landscape pattern is by shaded relief maps (Pike and Thelin,
1989). This approach allows the delineation of the major fault
and ring structures and the characterization of the density-
range (Hmaximum-Hminimum) within a mountain feature,
were used to parametrically represent the Valles Marineris
chasma (Miliaresis, 2001a).
% en ©
Figure 3. The 1-degree DEM of the Grand Canyon merged with the 1-degree DEM of the Marble Canyon.
roughness of the landscape by visual interpretation (Figure 2).
The major disadvantage is that we can not establish a metric
system that could compare the landscape of two different
physiographic zones in a quantitative and less subjective
manner. The tributary canyons of the study area are clearly
observable in Figure 2 indicating a similarity with the formation
of Valles Marineris canyon system.
841
2.2 Study area
The Grand Canyon lies close to the borders of Utah and
Nevada. The canyon system trends from longitude -111° to -113
and covers an area of approximately 4937 sq. km. In places the
canyon floor reaches a depth of 1800 m which is 6 to 7 times
sallower compared to the depth of the Valles Marineris chasma.
The width of the Grand Canyon varies from 16 km at the