“…Oxygen content, pH, and electrical conductivity were measured in the field with electrodes placed in flow cells. Hydrochemical parameters (alkalinity; benzene, toluene, ethylbenzene, xylene, naphthalene, Mn, Fe, Si, Al, Mg, NH 4 , Ca, K, Na, Cl, SO 4 , H 2 S, NO 2 , NO 3 , CH 4 , and dissolved organic carbon contents) and sedimentological parameters (lime, humus, sand, clay, silt, carbon, and nitrogen contents) were determined by using Dutch NEN standards and laboratory procedures. Samples were grouped based on chemical characteristics by using principal-component analysis and cluster analysis (Systat 7).…”