ABSTRACT

To better understand the biogeochemical factors affecting seasonal variations of major Greek river water composition, multivariate analyses on four seasonal data matrices of thirteen major Greek rivers and tributaries have been applied. The main factors governing river water composition were “carbonate dissolution”, which is the most important factor in spring, autumn and winter, and “pollution”, which is most important in summer. Less important factors are “biological activity”, which predominates during the dry seasons and “sodium chloride enrichment”, which slightly influences river waters, primarily in spring, due to flushing processes. The Greek river catchments are characterized by different climatic, hydrographic, morphologic, petrographic and vegetative features and varying pollution impact. Nevertheless, biogeochemical processes controlling river composition appear to follow certain common seasonal trends, as they would be a part of an integrated ecosystem.