Study On The Ambient Noise In Coastal Waters Of Northern Jiangsu Province

The coastal area of Northern Jiangsu is located on the coast of the Yellow Sea,with a coastline of 744 kilometers.It has a vast coastal area and sufficient wind energy,which is conducive to the development of clean and convenient wind power projects and coastal shipping projects.In recent years,with the development of offshore wind power generation technology,the number of offshore wind power projects in the coastal areas of Northern Jiangsu is increasing.At present,there are many offshore wind farm projects in the coastal areas of Northern Jiangsu,such as Xiangshui sea area,Binhai sea area,Sheyang sea area,Dafeng sea area,Dongtai sea area,such as Donghai area and qidonghai area.A wind farm barrier is formed in the coastal areas of Northern Jiangsu,which provides a large amount of power energy for many cities in China.It is in line with the plan of advocating the development of clean energy in China China's third largest energy source.At the same time,with the increase of sea shipping,the number of large-scale ports in the coastal area of Northern Jiangsu is increasing,and the number of ships is increasing,which results in the contribution value of noise generated by human activities to the marine environment noise in the coastal area of Northern Jiangsu is increasing.The underwater noise generated by many marine engineering facilities in the coastal area of northern Jiangsu poses a threat to the marine ecological environment,and there is an urgent need for quantitative analysis of the underwater noise in the coastal area of northern Jiangsu.In order to quantify the intensity and impact of underwater noise in sea areas where different conditions and different noise sources exist,this study divides the coastal waters of northern Jiangsu into coastal waters in northern coastal areas,Dafeng seas,such as northeast seas,and southeast seas for underwater For noise measurement,the underwater noise data and basic environmental elements during the measurement process were also obtained.Then use the matlab program to calculate the noise power spectrum and 1/3 octave spectrum of the underwater noise data,analyze the time-frequency characteristics,spatial distribution,and changes with engineering and environmental factors of the north Jiangsu sea noise,and finally discuss Its impact on typical marine life in the sea.Research indicates:(1)In the analysis of the time and frequency domain characteristics of underwater noise,the underwater environmental noise in the coastal areas of northern Jiangsu is mainly acoustic signals below 1000 Hz.For example,there are different noise source forms and sea conditions in the east,Dafeng and coastal areas,causing water.There is a certain difference in the time-frequency characteristics of noise.This is mainly reflected in the underwater noise of seaports and offshore wind farms in areas such as the southeast sea area,Dafeng sea area,and northern coastal water area.The noise power spectrum in the northeast sea area is basically similar in the 20 ? 20000 Hz frequency band,and the change is small.(2)From 2016 to 2019,in the analysis of the relationship between the changes in the underwater environmental noise in the northern coastal waters of North Jiangsu and the southeastern seas and the working conditions of offshore wind farm projects,the spectrum levels of the underwater environmental noise in the two seas follow the wind The impact of power engineering is greater.In the offshore wind power engineering area,the underwater noise spectrum level shows the characteristics that the construction period is greater than the operation period,and the sea area with more wind turbines is larger than the sea area with fewer wind turbines.Analyzing the influence of underwater noise and hydrometeorological conditions,the correlation between the 1/3 octave spectrum level of underwater noise and sea surface wind speed shows that high frequency is greater than low frequency,and shallow water is greater than deep.(3)If the southeast sea area is close to the economic fish migration area,the underwater environmental noise measured in the port area,wind farm area and fish migration area in the sea area in July 2016 and July 2018 is horizontal and vertical The distribution characteristics in the direction are analyzed.In the horizontal geographic distribution characteristics,the underwater noise distribution in the port area and wind farm area shows that the near-shore sea area is larger than the far-shore sea area,and the main noise frequencies of the fish migration area are 400 Hz,600Hz,and 800 Hz.In the vertical distribution characteristics,the three sea areas exhibit different distribution characteristics.Among them,there are many types of noise sources in the atmosphere and ocean in the special port area,which causes the underwater environmental noise spectrum level below 200 Hz to appear shallower(1m)than other Deep waterphenomenon.(4)The underwater noise in the northern Jiangsu area is mainly low-frequency signals below 1000 Hz.The noise data measured in 2018 in each sea area shows that the main frequency of the noise is related to the economic species of northern Jiangsu(large yellow croaker,small yellow croaker,octopus,croaker and silver etc.)There are overlapping or similar parts,so they interfere with their communication,foraging,reproduction and other behaviors.The submarine environment noise is complex and changeable because of the flat continental shelf,silty bottom and many tidal channels in the coastal area of North Jiangsu.In this paper,the measured data of different sea areas in north Jiangsu are analyzed,and the effect of underwater noise on typical marine organisms is discussed,the research results can provide data reference for marine management,marine engineering reasonable planning and marine ecological protection.