220
G. Kite and A. Pietroniro
backscatter. The vertically polarized transmit and receive signal on the ERS series of
satellites is much more sensitive to surface winds and waves than the same frequency
C-HH SAR onboard the Radarsat satellite. This was clearly shown by Barber et aI.,
(1996) for flood delineation along the Assiniboine River, Manitoba, Canada. They
concluded that C-HH data acquired at large incidence angles (greater than 45 degrees)
maximized their ability to detect flooded areas through specular reflection of the
incident wave.
10.3 Lake and Reservoir Area Estimates
There are many examples of lake and reservoir area estimates that rely on the contrast
of the near-infrared and visible wavelengths for coastline detection. This marked
contrast was demonstrated with two images of the Aral Sea in UsbekistaniKasachstan
as shown by Foster and Parkinson (1993). Using a DMSP daytime visible image from
1973 and a NOAA 11 acquired visible image from 1990, the dramatic reduction in
area of the inland sea (due to irrigation diversions from the in-flowing rivers) is
clearly demonstrated (Fig. 10.3). EI-Baz (1989) used stereo photographs from space
shuttle flights in 1981 and 1984 to show a difference of more than 20 metres in the
level of Lake Nasser between these dates. Such information was no doubt available
from water level gauges but the technique would be useful for lakes that are not
routinely measured.
Mouchot et aI. (1991) used Landsat TM for a morphological analysis of water
bodies in the Mackenzie Delta, northwestern Canada. The Mackenzie Delta has an
area of 12,000 km 2 and contains a complex interconnected network of many thousands oflakes, ponds, channels and waterways (Roberts et al., 1994). Subtle temporal
changes in the water regime result in a limnological network that is sporadically
Fig. 10.3. DMSP daytime images of the Aral Sea acquired in August, 1973 (left) and September, 1990
(right) showing the shrinkage of the sea and enlarged islands. An irrigated floodplain at the bottom
centre of both images is also clearly visible (after Foster and Parkinson, 1990)
G. Kite and A. Pietroniro
backscatter. The vertically polarized transmit and receive signal on the ERS series of
satellites is much more sensitive to surface winds and waves than the same frequency
C-HH SAR onboard the Radarsat satellite. This was clearly shown by Barber et aI.,
(1996) for flood delineation along the Assiniboine River, Manitoba, Canada. They
concluded that C-HH data acquired at large incidence angles (greater than 45 degrees)
maximized their ability to detect flooded areas through specular reflection of the
incident wave.
10.3 Lake and Reservoir Area Estimates
There are many examples of lake and reservoir area estimates that rely on the contrast
of the near-infrared and visible wavelengths for coastline detection. This marked
contrast was demonstrated with two images of the Aral Sea in UsbekistaniKasachstan
as shown by Foster and Parkinson (1993). Using a DMSP daytime visible image from
1973 and a NOAA 11 acquired visible image from 1990, the dramatic reduction in
area of the inland sea (due to irrigation diversions from the in-flowing rivers) is
clearly demonstrated (Fig. 10.3). EI-Baz (1989) used stereo photographs from space
shuttle flights in 1981 and 1984 to show a difference of more than 20 metres in the
level of Lake Nasser between these dates. Such information was no doubt available
from water level gauges but the technique would be useful for lakes that are not
routinely measured.
Mouchot et aI. (1991) used Landsat TM for a morphological analysis of water
bodies in the Mackenzie Delta, northwestern Canada. The Mackenzie Delta has an
area of 12,000 km 2 and contains a complex interconnected network of many thousands oflakes, ponds, channels and waterways (Roberts et al., 1994). Subtle temporal
changes in the water regime result in a limnological network that is sporadically
Fig. 10.3. DMSP daytime images of the Aral Sea acquired in August, 1973 (left) and September, 1990
(right) showing the shrinkage of the sea and enlarged islands. An irrigated floodplain at the bottom
centre of both images is also clearly visible (after Foster and Parkinson, 1990)