Optical remote sensing of microphytobenthic biomass: a method to monitor tidal flat erodibility
- Authors
- Publication Date
- Jan 01, 1998
- Source
- OpenGrey Repository
- Keywords
- Language
- English
- License
- Unknown
Abstract
A basis to monitor erosion shear stress of tidal flat surfaces by means of optical remote sensing has been developed. Erosion shear stress and corresponding bio-geochemical parameters of different tidal flats were measured during five years in the Sylt/Roemoe Bight in Germany. A significant dependence between the erosion shear stress and the benthic diatom chlorophyll a concentration in the uppermost 1 mm layer was found for the muddy areas. This dependence decreases with decreasing grain-size fraction <63 #mu#m. For stations with low phytobenthic coverage a weak dependence of erosion shear stress on grain-size fraction <63 #mu#m was found. Using optical techniques two main classes can be distinguished from ground based measured high resolution reflectance spectra. The first class contains information on the sediments type i.e. grain-size fraction <63 #mu#m. The second class corresponds to the phytobenthos which can be subdivided into benthic diatoms and other phytobenthic species. A significant correlation was found between reflectance spectra and grain-size fraction <63 #mu#m and also between reflectance spectra and the benthic diatom chlorophyll a concentration. So the erodibility of tidal flats can be mapped with optical remote sensing when the benthic chlorophyll a concentration and sediment grain-size fraction <63 #mu#m are used for estimation of the erosion shear stress. Optical measurements and erosion shear stress measurements and their relationships are discussed. (orig.) / Special print from: Senckenbergiana maritima (1998), 29, (1/6), p. 77-85 / Available from TIB Hannover: RA 3251(99/E/4) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische Informationsbibliothek / SIGLE / DE / Germany
