LINKING ARCHIVAL AND REMOTE SENSED DATA FOR LONG TERM ENVIRONMENTAL MONITORING

The broad objective of this paper is to illustrate how archival/historical and remote sensed data can be used to complement each other for long term environmental monitoring. One of the major constraints confronting scientific investigation in the area of long term environmental monitoring is lack of data at the required temporal and spatial scales. While remote sensed data have provided dependable change detection databases since 1972, long term changes such as those associated with typical climate scenarios often require longer time series data. The non-availability of data in readily accessible/usable formats for periods predating the conventional satellite data traditionally accessible to the public has for a long time restricted the scope of environmental studies to synoptic overviews covering short time scales. As a result, our understanding of different ecosystem processes has been informed by thin data incapable of yielding plausible explanations. One way to improve our understanding of ecosystem processes is by cross-linking different forms of data at different temporal scales. Unfortunately however, most research work has tended to marginalize the utility of the latter in environmental monitoring. While the accuracy of data from these records is often source-specific, varying from place to place depending o