310 
Fig. 5: 
Monitoring of progress and impact of channel dredging, 
Playgreen Lake area, Manitoba. A selection of 5 taken 
from a total of 18 relatively cloud free passes of ERTS 
is made displaying bands 7 (B, C, D, E), and 5 (A, E, G, 
H). Image B (16-5-73) shows the advance of the dredge 
to that date; progress can be followed on C (20-9-73) 
and D (14-7-74). The increase in impact of dredge spoil 
is shown on F, G, H (dates respectively the same as B, 
C, D). E shows the area in spring (23-4-74), note small 
amount of inundation. Note the change in turbidity 
patterns (light tones) between G and H.