ABSTRACT

By virtue of the survey data in May, September and October 1993, Cu content in Jiaozhou Bay water body represented its variation range of 1.57–3.57 μg/L, which abides by the national seawater quality standard of Class I (5.00 μg/L). It unveiled that in May, September and October, the entire water of Jiaozhou Bay was not contaminated by Cu at all. In May, the variation range of Cu content in the bay's waters was 1.57–3.57 μg/L. In the eastern coastal waters of Jiaozhou Bay, the Cu content got to a relatively high value, which was 3.57 μg/L. In September, Cu content in the waters of Jiaozhou Bay showed its variation range of 1.82–3.08 μg/L. In the eastern coastal waters of Jiaozhou Bay, the Cu content got to a high value, 3.08 μg/L. In October, Cu content in the waters of Jiaozhou Bay provided the variation range of 1.80–2.78 μg/L. In the mouth waters of Jiaozhou Bay, the Cu content got to a relative high value, 2.78 μg/L. From the angle of Cu content, the water quality of Jiaozhou Bay had reached high quality. The water was clean, and was not polluted by Cu content at all. The Cu content in the waters of Jiaozhou Bay mainly came from three sources, the transportation of atmospheric deposition, the transportation of offshore ocean currents and the transportation of surface runoff. Thus, human activities brought the Cu content to the land and ocean, and reached the waterbody of Jiaozhou Bay through these three paths. Even so, the atmosphere, ocean and land did not get polluted by Cu content at all. The author further builds a model block diagram to present the paths of Cu content in the migration process. The Cu content from the transportation of atmospheric deposition was 3.08–3.57 μg/L, from the transportation of offshore ocean currents was 2.78–3.49 μg/L, and from the transportation of surface runoff was 2.64 μg/L. The order of Cu content transported from different sources in descending order is: Cu content transported from atmospheric deposition> Cu content transported by offshore ocean currents> Cu content transported by surface runoff. From this, the author proposed the quantity and distance transported by different paths: 1) Transport substance by atmospheric deposition is the best way for the earth to deliver, with high content and long distance; 2) Transport substance by offshore ocean currents is the second way for the earth to deliver, with low content and short distance; 3) Transport substance by surface runoff is the final option for the earth to deliver, with low content and short distance.