VERTICAL VARIATION CHARACTERISTICS OF PETROLEUM CONCENTRATION AND BACKSCATTER COEFFICIENT IN PETROLEUM-POLLUTED WATER BODY

摘要

August 25th to 27th, 2018, in-situ data which was used to analyze the vertical variations characteristics of petroleum concentration and backscattering coefficient, was collected at Dalian port which is located in Liaoning province, China. The analytical results of these data drew three conclusions. First of all, the regime of vertical variation of petroleum concentration is complicated, and the concentration does not decrease or increase gradually with depth increasing, due to the fact that ebb and flow of different time and stations could influence current in different way. Secondly, the minimum and second minimum of backscattering coefficient of each station are at 700nm and 590nm respectively. By the way, magnitude of backscattering coefficient is similar at 420nm, 442nm, 470nm and 5!0nm, and backscattering coefficients of these stations vary with depth consistently. Finally, there are three kinds of vertical variations of total backscattering coefficient in this study area, they are abrupt growth, steady growth and single hump. Abrupt growth backscattering coefficient varies less in the water column but growth quickly near 11.5m below the sea surface. Steady growth backscattering coefficient growth gradually with depth increasing. While single hump backscattering coefficient still has three subtypes: peak value at sea surface, peak value at middle-level of water column and peak value at bottom of water column. The maximum of backscattering coefficient of peak value at sea surface type lie in 0.5～2.5m below the sea surface, and the maximum of backscattering coefficient of peak value at middle-level of water column is located in 7～10m below the sea surface, and the maximum of backscattering coefficient of peak value at bottom of water column always occurs in the region of 10～12.5m.