Ansätze zur Regionalisierung bei sehr geringer Datendichte und inhomogener Datenverteilung -- Erläuterungen am Beispiel des regionalen Verteilungsmusters von Phosphat-Flußraten über die Sediment-Wasser-Grenzfläche im östlichen Süd-Atlantik

The often restricted amount of data obtained in the field and their spatial distribution are major problems in the interpretation of data for possibly underlying local structures. A procedure for regionalisation on the basis of very low data density is presented for a marine geochemical example. The aim was to evaluate a regional distribution pattern for diffusive benthic phosphate flux rates in the eastern South Atlantic. With the help of geostatistic methods (variogram) it could be shown that the investigated locations correlate spatially and structurely up to a distance of 7° (ca. 800 km) regarding phosphate release and fixation. On the basis of these results a regionalisation was carried out using the krigeage-method. The regional structures of this distribution pattern showed the expected relationship between the nutrient flux rates and the organic matter primarily produced in the photic zone. In case the used procedure was not applicable due to regional very different data density an interpretive fit of the computerised regionalisation was carried out with correlative references to rate determining factors such as primary production, water depth and current patterns. A map of regional distribution patterns was produced showing good agreement with recent oceanographical and sedimentological conditions.