海上航船分布及其对海洋环境噪声的影响

SHIP DISTRIBUTION IN OPEN SEA AND ITS IMPACT ON OCEAN AMBIENT NOISE

当代水下目标探测向低频远程发展,海洋环境噪声的低频特性倍受关注,航船噪声是海洋中的主要低频噪声源。近几十年来,海上航运量迅速增长,导致海洋环境低频噪声大幅升高,增加了海洋环境的噪声污染。本文依据港口进出航船信息库和船舶自动识别技术数据库资料,分析历史航船分布数据,依据获得的某开阔海域航船分布规律,建立数值模型估计了航船噪声源对低频海洋环境噪声特征的影响。结果表明,日进、出港的航船数近似满足正态分布,近海开阔海域单位面积、单位时间内的航船数近似满足泊松分布;由于海上航船的影响,海洋环境噪声强度呈明显的水平非均匀分布状态。

With the development of underwater acoustic detection to the direction of low frequency and long range, properties of low-frequency ocean ambient noise have attracted more attention, of which shipping noise is the main source. Many studies show that the average value of low-frequency ocean ambient noise level has risen significantly in recent decades because of rapid development of shipping activities. Based on ship in-and-out information of a certain port and ship automatic identification system database, we analyzed statistically the historical data during a certain period and estimated the impact of shipping noise on the ocean ambient noise level. The results show that the number of ships daily in and out of the port shows normal distribution and the number of ships per area in unit time approximates to Poisson distribution. In addition, we investigated the statistical distribution of ships in the open sea, and the impact signals at different receivers. Result shows that the strength of ocean ambient noise is horizontally non-uniform caused by shipping noise.