水体盐度变化对声学测沙的影响试验研究  

Experiment study on measuring suspended sediment concentration in saline waters with different acoustic instruments

作　　者：邵宇阳[1] 吴乾坤 唐玉林 张志林 SHAO Yu-yang;WU Qian-kun;TANG Yu-lin;ZHANG Zhi-lin(College of Harbour,Coastal and Offshore Engineering,Hohai University,Nanjing 210024,China;Survey Bureau of Hydrology and Water Resources of Changjiang Estuary,Hydrology Bureau of Changjiang Water Resources Commission,Shanghai 200136,China)

机构地区：[1]河海大学港口海岸与近海工程学院,江苏南京210024 [2]长江水利委员会水文局、长江口水文水资源勘测局,上海200136

出　　处：《泥沙研究》2023年第2期30-36,73,共8页Journal of Sediment Research

基　　金：国家自然科学基金联合基金重点项目(U2040203);国家自然科学基金项目(52011540388);上海市水务局科研项目(沪水科2020-02)。

摘　　要：在河口海岸地区利用声学仪器获取高时空分辨率的水体含沙量时,盐度的时空变化会对不同频率声学仪器的量测结果产生较大影响。为认识水体盐度变化对声学测沙的影响,利用三种频率的声学仪器和两种黏性泥沙开展了一系列室内试验。试验成果显示:含沙量与回声强度之间存在线性关系,随声学频率、泥沙粒径和水体盐度的变化而发生改变;随着水体盐度的逐渐增加,回声强度会迅速增强并逐渐达到饱和值,声学频率越高回声强度越容易达到饱和值。基于试验结果总结了盐度对回声强度的影响规律,建立了盐度影响下回声强度的修正方法,可获得更为合理的含沙量与回声强度之间的线性关系。Acoustic instruments are widely used in estuarine and coastal areas to obtain high-resolution suspended sediment concentration(SSC).However,the salinity varies temporally and spatially which influence the observations by acoustic instruments with different frequencies.Laboratory experiments were carried out for two different cohesive sediments by three different acoustic instruments characterized by their frequencies.The results show that there is a variable linear relationship between suspended sediment concentrations and echo intensity depending on acoustic frequency,sediment size and water salinity.With a gentle increase of water salinity,the echo intensity increases rapidly until saturated,with a higher acoustic frequency at the saturation state more evidently.A modified acoustic backscatter formula that includes the influence of salinity is also proposed to a better prediction of the SSC-AB relationship.

关 键 词：回声强度 盐度变化 含沙量 细颗粒黏性泥沙 

分 类 号：TV148.4[水利工程—水力学及河流动力学]