The Mode and Definition of the Content Variation Angle by Yang Dongfang

This paper studies the content change of Pb in the surface and bottom water of Jiaozhou Bay and its settlement process according to the investigation materials in May, August and October in the year 1991. The author comes up with the definition and mode of Yang Dongfang content variation angle. Through the changing process of the content variation angle, this study determines the changing degree to which the substance content varies over time, and gives the standard of changing degree. Classifying the Yang Dongfang content variation angle in the interval [-90°,90°] to many intervals [-90°,-60°,-45°,-30°, 0°,30°,45°,60°,90°], this study elaborates the standard of changing degree to which the substance content changing over time, and quantitatively reveals the horizontal changing process of substance content in the surface and bottom layers and vertical changing process between surface and bottom layers. Calculating the result based on the definition and mode of Yang Dongfang content variation angle, the author gets the conclusion that the Yang Dongfang content variation angle is 79.15°in the surface water from May to August, and -83.96°from August to October. In the bottom water, it is 81.68°from May to August and -84.25°from August to October. According to the scale of temporal and spatial variation, human activity has directly increased the Pb content in surface layer to a higher degree, and may also radically decrease the Pb content to a lower level. Furthermore, the Pb content in the bottom and surface layers varies the same after getting through the water body. As the changing over time, the decrease of Pb content in surface and bottom water body is consistent under the effects of gravity and water stream. Therefore, human beings must keep a clean marine environment and reduce the emission of Pb content as far as possible.