The Change Process of PHC Content from Sources in Water Bodies

Based on the investigation data of Jiaozhou Bay in May, August and October, 1992, the variation of PHC content in the surface and bottom layers and the deposition process were studied. According to the definition and model of Content Change Angle of Dongfang Yang, the calculation results show that in the surface water, the Content Change Angle of Dongfang Yang is - 0.34° from May to August, and 0.28° from August to October. In the bottom water, from May to August, the Content Change Angle of Dongfang Yang is - 0.91°, and from August to October, the Content Change Angle of Dongfang Yang is 0.22°.According to the scale of time and space, in May, the oil spills transported PHC content to Jiaozhou Bay, but in August, there was no PHC content from any sources. From May to August, PHC content decreased slowly and to a relatively low level. In October, open seas currents transported PHC content to Jiaozhou Bay. From August to October, PHC content increased slowly and to a higher level. After PHC content passed through the water body, from May to August, the settling PHC content in bottom increased slowly and the increase was relatively small. From August to October, the settling PHC content in bottom increased a little slowly. Therefore, the author puts forward the change process of the material content transported from sources in water bodies: when materials are transported to a water body from sources, the material content in the surface of the water body will rise faster than that in the bottom, and the material content in both the surface and the bottom will start to rise slowly. When materials are not transported to a water body from sources, the material content in the bottom of the water body will decline faster than that in the surface of the water body, and the material content in both the surface water body and the bottom water body will begin to decline slowly.