The objective of this study is to clarify the statistical characteristics of pollutants deposited in urban areas, taking account of stages (road surfaces, street inlets and streams) and land uses where they accumulated, from surveys over a period of 16 years in Kyoto City. The result of correlation analysis showed that there are intimate relationship between grain size and such pollutants as organic matter and nutrients. It showed the dependence of pollutants on grain size. After principal component analysis, the distribution of principal factor loading showed that the first and the second components meant the type of pollution and the physical property of pollutants. The distribution of the principal factor score showed that each land use had different pollutant characteristics. On the other hand, the characteristics of the pollutants that accumulated on a road surface were shown to be affected by storms, and nutrients were more likely to run off in a storm than organic matter. The content rate of pollutants accumulated in a stream was shown to decrease in proportion to the progress of sewer construction, but it was also shown that the rate of some pollutants has not changed in the area of a separate sewer system.

As a result, some valuable information for the control of nonpoint pollutants in urban area was obtained.

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