MEASUREMENT OF TOTAL LOAD DURING SNOWMELT RUNOFF USING AN ULTRASONIC ATTENUATION SPECTROMETER WITH AN IMPROVED FLOW CELL

Abstract

 The flow cell type ultrasonic attenuation spectrometer was the first suspended sediment measuring system to be installed in a river, in 2017. Although wash loads had been measured in previous experiments, there were problems with the sampling method and the flow cell structure for the measurement of sediment containing particles larger than fine-grained and medium-grained sand. In this study we increased the sample volume, improved the particle size distribution determination method, and measured suspended sediment during snowmelt runoff using an ultrasonic attenuation spectrometer with an improved flow cell. We confirmed that this spectrometer could measure the concentration and the particle size distribution of suspended sediment with diameters of 2 mm or less and wash load. Using this data, it was possible to estimate total load by particle size class.