from
me;
,000)- of
th time.
(1973)
f many
aration.
zations
exist that
>flectances
ough only
There
in envi-
ing marine
ecting tool
1975.
ty, 1976).
nal and
ple, is
ations, to
| in the
System (DCS)
formation to
area of
S, while
stant flow
This
of the
rs, 1975).
ncluding the
of these
th
vhen coupled
are also
>ctiveness
j, such as
ng as a
3) use of the MSS band 7 (outside the spectral sensitivity range
of film) is essential; and
4) successive images can be overlaid, without special processing
to rapidly assess temporal change (Deutsch and Ruggles, 1974; Weisnet
and others, 1974; Williamson, 1974; Rango and Anderson, 1974; and Moore
and North, 1974).
Landsat imagery shows promise as a tool to monitor energy-related
development in Alaska. Examination of the vegetative cover, on a
false-color Landsat image of the Umiat oilfield, revealed only one
indication of scarring of the delicate tundra as a result of the
intense oil exploration in thís area in the late 1940's and early 1950's.
This suggested that the environmental effects of oil exploration were
not spreading but rather were healing. This conclusion was largely
substantiated by low-level helicopter surveys undertaken by
R.L. Detterman in the summer of 1973 and reported by Lathram (1973).
One short, clear-dozed, and repeatedly used trail near Umiat still
formed a marked scar, which upon close examination is visible on Landsat
images.
In 1975, George C. Taylor. Jr. (written communication) studied five
adjoining Landsat frames of bands 6 and 7 at a scale of 1:1,000,000.
These images were mosaicked and used with available geologic maps,
hydrologic data and lines of instrumentally determined benchmarks in a
geohydrologic reconnaissance for the Organization of American States of
the Pantanal region in the Alto Rio Paraguai basin, Brazil. The
Landsat imagery used in conjunction with hydrologic and geologic infor-
mation obtained during a recent UNESCO/UNDP project with the Government
of Brazil made possible a regional synthesis of information that had not
been feasible at an earlier stage.
The Landsat imagery showed that the surface configuration of the
Pantanal is presently dominated by an alluvial fan of the Rio Taquari,
which occupies and extends almost completely across the central Pantanal.
The Taquari fan, which extends a maximum distance of about 225 km from
north to south and 250 km from east to west, covers an area of about
50,800 km?. Moreover, the imagery indicates that aggradation of the
Taquari fan bas now locked the Rio Paraguai in its present channel con-
trolled by bedrock thresholds along the western margin of the Pantanal
depression. Using the drainage lines defined by the Landsat imagery
together with available lines of benchmarks, it was possible to construct
an approximate topographic map, scale 1:2,000,000, with 10-m contours on
the surface of the Pantanal alluvial fill. This map indicates that the
rapid aggradation of the Taquari fan has deflected and ponded drainage
to the north, south, and west of the fan creating extensive swamps and
shallow lakes. Ground-water reconnaissance indicates that the water
table in the Pantanal alluvium is essentially a subdued replica of the
land surface, hence the configuration of the water table is similar to
that of the surface topography constructed with the use of Landsat
imagery.
17