Comparison of calibration characteristics of different acoustic impact systems for measuring bedload transport in mountain streams

Abstract. The Swiss plate geophone (SPG) system has been installed and tested in more than 20 steep gravel-bed streams rivers, related studies generally resulted rather robust calibration relations between signal impulse counts transported bedload mass. Here, we compare this with three alternative surrogate measuring systems. A variant of the SPG uses same frame (housing) set-up but an accelerometer instead a sensor to measure vibrations (GP-Acc, for accelerometer). miniplate (MPA) smaller dimension impact is embedded elastomer material system. Japanese pipe microphone (JPM) 1 m long version that many Japan. To performance four systems, used measurements direct samples from field sites outdoor flume facility controlled sediment feed. At our sites, systems showed partly large temporal variations background noise level, which may have impaired obtained during certain time periods. Excluding these periods, SPG, GP-Acc, JPM all relations, whereas MPA poorer at sites.