Use of satellites and other remote sensed images

Land based surveys are time consuming, especially where national data are being collected. A survey of saltmarsh vegetation in Great Britain (Burd 1989) took eight years to complete. Monitoring saltmarsh change in southeast England between 1972 and 1988 (Burd 1992) was also relatively expensive and time consuming. Neither study is likely to be repeated using traditional survey techniques. Other methods of large scale, more frequent survey would be more appropriate. In this context satellites may provide a possible alternative.

In the UK this approach has been initiated by English Nature and the Environment Agency National Centre for Environmental Data and Surveillance (NCEDS). The study has used combined LIDAR and CASI data collected by airborne instruments to monitor coastal habitats. Shingle is included and the case study site is Rye Harbour. The results are due in 2003.

The launch of the European Union satellite, ENVISAT should help provide more data that can be used for monitoring the coast. There are several projects testing the value of this system, one such being the European Space Agency funded 'CoastWatch' programme begun in 2003. When combined with lower level airborne instruments a powerful tool could be developed. There is already calibration of remote sensed images for saltmarshes and it should easily be possible to use this approach for other coastal habitats. The issue needs to be addressed by a concerted effort, which brings together those who have knowledge of the coastal environment and those with technical expertise in remote sensing and GIS.

References

Burd, F. 1989. The Saltmarsh Survey of Great Britain. An Inventory of British Saltmarshes. Research & survey in nature conservation, 17 Nature Conservancy Council, Peterborough.

Burd, F. 1992. Erosion and Vegetation Change on the Saltmarshes of Essex and North Kent between 1973 and 1988. Research & survey in nature conservation, 42 Nature Conservancy Council, Peterborough.