||Application of Numerical Classification in Ecological Investigations of Water Pollution.
Boesch., Donald F. ;
||Virginia Inst. of Marine Science, Gloucester Point.;Corvallis Environmental Research Lab., Oreg. Marine and Freshwater Ecology Branch.
||Special Scientific-77; EPA-R-803599; EPZ/600/3-77/033;
Water pollution ;
Cluster sampling ;
Statistical quality control ;
Multivariate analysis ;
Indicator species ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
Numerical classification encompasses a variety of techniques for the grouping of entities based on the resemblance of their attributes according to mathematically stated criteria. In ecology this usually involves classification of collections representing sites or sampling periods, or classification of species. Classification can thus simplify patterns of collection resemblance or species distribution patterns in an instructive and efficient manner. Procedures of numerical clssification are thoroughly reviewed, including data manipulations, computation of resemblance measures and clustering methods. Agglomerative clustering methods which distort spatial relationships and intensely cluster are often most useful with ecological data. The usefulness of numerical classification is demonstrated for objective analysis of the data sets resulting from field surveys and monitoring studies conducted for the assessment of effects of pollution.