Decreasing and Migration Process of PHC Content in Central Jiaozhou Bay
Authors: Yang Dongfang , Li Haixia , Lin Dong , Zhang Yuan , Wang Qi 
Published: April 2020

Abstract
Based on the survey data of Jiaozhou Bay in May, August and October 1992, the migration and variation of PHC content of the oil spill in Jiaozhou Bay were studied. It was found that oil spill originally occurred in central Jiaozhou Bay in May, and its PHC content was 0.042mg/L. A series of concentric circles with different gradients formed around there, and there was a descended distribution trend from the center to the periphery along the gradient. The content of PHC decreased from 0.042mg/L at the center to 0.012mg/L in the southwest water, 0.024mg/L in the northwest water, 0.012mg/L in the northern water, 0.020mg/L in the northeast water, 0.014mg/L in the eastern water and 0.010 mg/L in the southeast water. The PHC content in these waters ranged from 0.010mg/L to 0.042mg/L. With horizontal absolute loss velocity model of material content, it was calculated that the horizontal absolute loss velocity of PHC content in the surface waters from the central water to the southwest water in May was 0.36 Yang Dongfang absolute number, to the northwest water 0.25 Yang Dongfang absolute number, to the northern water 0.52 Yang Dongfang absolute number, to the northeast water 0.31Yang Dongfang absolute number, to the eastern water 0.58 Yang Dongfang absolute number and to the southeast water 0.50 Yang Dongfang absolute number. Therefore, with the central water of Jiaozhou Bay taken as the source of oil spill at sea, there was a descended PHC content distribution trend from the center to the periphery along the gradient, and the horizontal absolute loss velocity of PHC content ranged from 0.25 Yang Dongfang absolute number to 0.58 Yang Dongfang absolute number. With horizontal relative loss velocity model of material content, it was calculated that the horizontal relative loss velocity of PHC content in the surface waters from the central water to the southwest water of Jiaozhou Bay in May was 8.68 Yang Dongfang relative number, to the northwest water 5.95 Yang Dongfang relative number, to the northern water 12.38 Yang Dongfang relative number, to the northeast water 7.38Yang Dongfang relative number, to the eastern water 13.80 Yang Dongfang relative number and to the southeast water 11.90 Yang Dongfang relative number. Therefore, with the central water of Jiaozhou Bay taken as the source of oil spill at sea, there was a descended PHC content distribution trend from the center to the periphery along the gradient, and the horizontal relative loss velocity of PHC content ranged from 5.95 Yang Dongfang relative number to 13.80 Yang Dongfang relative number. The rising PHC content distribution order was: that of the southeast water < that of the southwest water < that of the northern water <that of the eastern water< that of the northeast water <that of the northwest water. The rising horizontal absolute (relative) loss velocity of PHC content order was: that of the northwest water < that of the northeast water < that of the southwest water <that of the southeast water< that of the northern water <that of the eastern water. With horizontal loss velocity model of Yang Dongfang material content, the terminal value and process value of PHC content form the central water toward the six directions can be calculated.