潮间带水沙多层位同步测量系统应用的初步研究

Calibration and Observation by Using a Water Level, Current Speed, and Turbidity Monitoring System in Coastal Areas

利用水压、光电转换原理研制成的多层位水沙同步测量系统（WCT 系统）不仅可测量潮间带水位随时间的变化系列、同一层位的浊度及流速，还可以同步观测这些参数在潮间带水流剖面不同层位上的变化。野外对比试验表明，WCT 系统获得的流速值与直读式流速仪的测量结果基本一致，平均相对误差为 14.52 %；悬沙传感器经野外现场率定获得悬沙浓度，平均相对误差为 21.96 %，精度比室内率定提高一倍以上。悬沙粒径是影响悬沙浓度测量精度的主要因素。此外，自然环境（如海水温盐度）的变化及仪器本身的特性也可能影响到测量结果。因此，WCT 系统在潮间带的水位、流速和悬沙浓度的观测和边界层研究方面有相当潜力。

:Based upon the principle of water pressure and the light-electric effect, an integrated system of water-level, current-speed and turbidity (WCT) meters has been developed. The sensors of water level and current meter have been calibrated in the standard flume in laboratory. The turbidity meter has been calibrated in the laboratory. And then, a field observation is carried out on the intertidal flat, in order to measure the water level, and five layers of current speed and turbidity synchronously within the water column. The results show that the average of relative error for the current speed is 14.52 % in comparison with that of direct-reading current meter deployed in the same layer. By in situ calibration using water sample filtration, the absolute suspended sediment concentrations are then obtained with a relative error of 21.96 %, which improve the accuracy greatly compared to that of laboratory calibration. Hence, the WCT System can be used for observation of water level, velocity of flow and suspended sediment concentration in the boundary layer study on intertidal flats. During the calibration, the effect of grain size was excluded. Moreover, the accuracy of WCT system is also found to be depended on natural environment (e.g. the seawater temperature and salinity) and characteristics of the instruments.