315 
mdix multi- 
Lcluding 
•electric 
lire long- 
■ 5 to 20 
onmental 
Ltrol 
l the future. 
A special 
•gram for 
project, 
i was 
The following 
1973). 
changes 
tion of 
Some aspects of these projects are shown in Fig. 4 and 5. The low 
cost figures and methods are dependent upon the availability of ERTS imagery. 
The fact that ERTS-1 produced about 18 cloud-free images in a period of about 
2 years for the area in Fig. 5, demonstrated that this dependence is not un 
warranted. 
CONCLUSION 
Environmental monitoring is important for proper management of 
natural resources. Environmental impact assessment and prediction forms an 
essential component of the evaluation process of resource alternatives. In 
Canada, the ERTS-1 satellite has provided repetitive coverage for most parts 
of the country varying from about 4 to 10 times a year. Such coverage gives 
a good opportunity to obtain baseline and reference data and to determine and 
evaluate many environmental changes for purposes of impact assessment. ERTS 
can also provide some assistance in environmental protection programs; however, 
airborne remote sensing systems are needed in combination with field observation 
in order to provide information with great detail. Remote sensing is considered 
to be particularly advantageous for the surveillance of large scale developments 
in northern Canada. 
i will 
on, 
tative 
borne 
onvent- 
easily 
osystems 
at an 
pie areas 
d on results 
ffice; 
ecosystems 
looding; 
to 
REFERENCES 
Fleming, E.A. 
1974: The Utilization of Satellite Imagery for Map Revision. 
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Hills, G.A., D.V. Love, D.S. Lacate 
1970: Developing a Better Environment. Ontario Economic Council, 
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Johnson, P.L. 
1970: Remote Sensing as an Ecological Tool. Proc. Helsinki 
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Jurdant, M., J.L. Belari, V. Gerardin, R. Wells 
1974: Ecological Land Survey. Proc. Toronto Workshop to Develop 
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Lacate, D.S. et al 
1970: Guidelines for Bio-physical Land Classification. Department 
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MacDowall, J., P.A. Lapp 
1973: Sensor Development, An Overview of Recent Canadian Experience. 
"Sec. Fifteen Years in Space", Vol. 31, American Astronautical Soc., 
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