Factors Explaining Sediment Concentrations of 16 Elements in 28 Japanese Eutrophic Lakes

To understand lake sediment environments, the concentrations of 16 elements in sediments and suspended particulate matter (PM) from 28 Japanese eutrophic lakes were analyzed. Use of some statistical analysis permitted them to be grouped into a) alkali metals and alkaline earth metals (Na, Mg, Ca, Sr, K), b) elements originating from soil particles or rock (Ti, Fe), c) elements having significant anthropogenic inputs (P, Cr, Cu, Zn), d) organic carbon and nitrogen. The ratio of PM to sediments decreased in the order c), d), a) and b). With the aid of a simple conceptual model, some significant factors were successfully shown to explain the sediment concentrations of respective groups: a) salinity of the lake water, b) Ti concentration in PM, which reflects the arrival rate of soil particles at the mid-point, c) TP concentration in lake water representing the anthropogenic load, d) chlorophyll a concentration in lake water divided by the area ratio of drainage to lake surface.