南海典型海域环境噪声时空变化特性及其产生机理研究

Ambient noise is an eternal background sound in the ocean. The noise's spatial and temporal distribution is affected by the noise source and the ocean acoustics wave guide, showing obvious vitiation characteristics. This project analyzes the spatial-temporal variation of ambient noise in typical areas of the South China Sea, reveals the mechanism of environmental noise generation, and demonstrates the relationship between the spatial and temporal distribution of ocean ambient noise, noise propagation channels, and various types of noise sources. Based on the research of the temporal and spatial characteristics of noise, an ambient noise model suitable for typical areas of the South China Sea is established. The model combines the noise source characteristics of the ship and the ship's distribution information based on the marine automatic identification system, and consider as the wind noise sources to realize the non-uniform dynamic modeling of the noise source, which can effectively represent the short-term change rule of the noise instead of the Long-term statistical average results in traditional noise studies. In addition, using the parabolic equation approximation method to model the horizontal non-uniform noise propagation wave guide can analyze the distribution characteristics of the three-dimensional noise field, and study the distribution characteristics of the noise field in different marine environments. Through the data analysis and model simulation results of this study, the general rules of the spatial and temporal changes of ambient noise in the typical areas of the South China Sea can be summarized, which can provide data and some research foundations for the environmental changes, developments and utilization of marine resources in the South China Sea, and can provide support for the underwater equipment design and use.

环境噪声是海洋中永恒的背景声场，其时空分布受噪声源和海洋波导共同影响，表现出明显的变化特性。本项目首先通过分析中国南海典型海域环境噪声时空变化规律，揭示环境噪声产生机理，论证海洋环境噪声时空分布与噪声传播信道以及各类噪声源之间的关系。在噪声时空特性研究的基础上建立适合南海典型海域环境噪声模型。该模型结合航船噪声源特性以及基于船舶自动识别系统的航船分布信息，并考虑风成噪声源等因素，实现噪声源的非均匀动态建模，能够有效表征噪声的短时变化规律，而非传统噪声研究中的长时间统计平均结果。另外，采用抛物近似方法对水平非均匀噪声传播波导进行建模，可以分析三维噪声场分布特性，研究不同海洋环境下的噪声场分布结构特征。通过本项研究的数据分析和模型仿真结果，可以对南海典型海域环境噪声时空变化一般性规律做出总结，可为南海的环境变化、海洋资源开发利用、水下设备的设计和使用提供数据和研究基础。

在我国领海中，南海覆盖面积广大，海洋环境类型丰富，包含了浅海、大陆架陡坡、深海以及岛礁等典型的海洋环境；另外，由于气候和洋流的作用，使南海海域水文环境呈现强烈的时空不均匀分布。近年来，南海海域的海洋资源开发、渔业活动和航运运输随着经济发展和政策倾斜也呈现出更加活跃的状态。以上这些因素造成了南海环境噪声时空分布呈现出有别于其他海域的特点。本项目针对水声装备在南海使用中对海洋环境噪声时空分布规律的需求，通过对南海典型海域海洋环境噪声数据时空变化特性深入分析，获取浅海、大陆坡、深海以及岛礁等典型海域海洋环境噪声特性。研究过程中通过噪声谱相关的方法分析主要噪声源特性，研究噪声产生机理，通过组合风浪噪声源和航船噪声源特征构建符合南海典型海域的海洋环境噪声模型，并用典型南海噪声数据对模型进行校验。最后，以南海岛礁为例，分析岛礁区域环境噪声时空分布特点，显示出项目构建模型在南海复杂海域的适用性。