Concentration Distributions and Characteristics of Pollutions Containing in Sediment Samples in Lake Kojima

The distributions of nutrients and heavy metal concentrations in sediment samples taken from Lake Kojima were surveyed, and the results of these studies were as follows : 1) Samples taken from the sediment which had accumulated around the lumberyard, contained rich organic compounds, nitrogen, sulphide, titanium and chromium with low density and small particle size. 2) Phosphorus, cadmium, lead, iron and manganese were found to have accumulated at the mouths of the two rivers. 3) The sediment samples from the center area had higher densities and larger particle size, and contained a small quantity of organic compounds, nutrient salts and heavy metals. 4) The sedimentary quantity and speed were also estimated ; quantity and speed were 4.4×106 m3 and 16 mm·y-1, respectively. 5) Results were calculated using the principal component analysis of 20 items which showed that the 1st component contributed 70.0% of the original data, pointing out the general pollution index in sediments. The 2nd component contributed 10.8% of the original data pointing out the difference of sedimentaion.