Potential of using remote sensing techniques for Wadden Sea monitoring

Kerstin Stelzer
Brockmann Consult, Geesthacht, 21502, Germany
Kerstin.stelzer@brockmann-consult.de

ABSTRACT

Various policy-driven monitoring programs (e.g. TMAP, HELCOM) for the coastal zone have been set up over the past years. Their goal is to detect and assess natural and anthropogenic influences and their effects on these dynamic systems. The monitoring of intertidal flats and of coastal waters is both time consuming and cost intensive and in order to reduce these costs, the use of remote sensing techniques in different fields of application has been recently investigated in the framework of EU co-funded and user driven projects. Investigations are ongoing, as to how remote sensing techniques can be used to optimise operational monitoring programmes in order to fulfil the requirements of directives such as the Water Framework Directive or the Fauna Flora Habitat Directive.

Information concerning different components of tidal flats, such as the sediment, macro- and microphytes and blue mussel beds can be obtained by applying different methods to remotely sensed data (e.g. Linear Spectral Unmixing). Quantitative estimates of their position and areal cover can be retrieved, from which information concerning change and development phenomena can be deduced. Landsat images provide a good overview of larger tidal flat areas, however, when more detailed spatial information is required, airborne remote sensing should be used. Data from MERIS onboard of ENVISAT can be used to produce maps showing the distribution and concentration of chlorophyll-a, total suspended matter and yellow substance. In-situ measurement programmes can indeed be optimised by combining them with remote sensing techniques, and also to highlight areas with greater change or areas which should be under special observation. Remote sensing is not a substitution for in-situ measurements, but rather complements other measurements in operational monitoring programmes, as will be demonstrated.

Last Update: 2005-04-7