Author(s): Hesham Rabie Sayed Fouli
Linked Author(s):
Keywords: Sediment transport; Bed load transport; Suspended load transport; Physical and mathematical models; Passive and active tracer techniques; Spectralanalysis; Spectrum; Hydrophone; Flume; Torrent; Frequency; Frequency band; Time series
Abstract: Sediment transport is conventionally subdivided into bed load transport and suspended load transport. Many approaches have been tried out to assess sediment transport since a considerably long time. Among them are; physical models, mathematical models and formulae, in-situ monitoring yielding empirical formulae etc. In addition, relatively new techniques such as passive (e. g. iron, magnetic) and active (e. g. radio) tracer techniques have been tried as well (Ergenzinger and Schmidt, 1992). Banziger and Burch (1990) used a sensor whose core is a piezoelectrical crystal which generates an electric potential that can be measured when the crystal deforms due to collision with sediments. However, the full assessment of the sediment transport behaviour is not yet completely understood and almost all methods have shortcomings when they are used. In this paper, a method based on the analysis of the flow acoustics as well as the bed load acoustics while being transported is investigated. The idea briefly depends on the fact that different sediments produce different tones at different frequencies when they are transported along the stream. The spectral analysis of these acoustics in the form of sound waves (signals) is expected to be a sort of indicator for the sediments transported. The produced sound signals are being recorded via a sensitive hydrophone and then digitised using a Digital Audio Recorder (DAT). The recorded signals are then being analysed by studying their spectra. It is to be mentioned that the study is concerned only with the bed load transport and not the suspended load transport.
Year: 1999