Research On Spatiotemporal Sound Velocity Field Model Of Yangtze Estuary Based On Kriging Interpolation

The water conditions in the Yangtze Estuary are complex,affected by both runoff and tidal currents.The tide water from the outer sea enters the Yangtze Estuary at high tide,and the tidal water is mixed with the upstream runoff fresh water at low tide.This makes the sound velocity of the Yangtze Estuary complex and variable.The error seriously affects the accuracy of the water depth measurement;the maximum difference in sound velocity at the same position during the tide can reach 30 m / s,which has a huge impact on the underwater measurement work.Based on this,based on the measured water temperature and salinity measurement data in the Yangtze River estuary,this paper analyzes the research status at home and abroad,selects the calculation formula of the sound velocity in the Yangtze estuary waters,the law of the change of the sound velocity over time and space in the study area,and the Research on key technologies such as sound velocity calculation,and construct a spatiotemporal sound velocity field model in the Yangtze Estuary.The main work includes:1)Based on the data of the existing fixed stations,the distribution law of the sound velocity field in the Yangtze Estuary is analyzed.The principle and method of traditional sound velocity calculation are introduced,several commonly used calculation formulas are discussed,and their applicability is selected according to the characteristics of the sound velocity distribution law in the Yangtze Estuary.2)Through the calculation of the sound velocity in different sections of the Yangtze River estuary and analysis of its characteristics with time and space changes,the observation density of representative sound velocity profiles in different measurement areas during water depth measurement is improved,and the representative of the sound velocity profile is weakened to the greatest extent.Sexual error.3)By processing the calculated sound velocity and selecting appropriate interpolation methods to process the data,the law of sound velocity change with time and measurement depth of each station and the law of sound velocity change with time and space on a route areobtained and compared with Make the difference between the true value and verify its validity;when the accuracy reaches the water depth measurement requirements,expand the "line" data of a route into the "surface" data of a piece of water,and also make a difference with the true value to verify its effectiveness.