Laboratory investigation on the effect of particle size, water flow and bottom surface roughness upon the response of an upward-pointing optical backscatter sensor to sediment accumulation
Thomas, Séverine, Ridd, Peter V., and Renagi, Ora (2003) Laboratory investigation on the effect of particle size, water flow and bottom surface roughness upon the response of an upward-pointing optical backscatter sensor to sediment accumulation. Continental Shelf Research, 23 (16). pp. 1545-1557.
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Upward-pointing optical backscatter sensors (OBS) have been recently introduced to measure sediment accumulation in situ. Here, the effect of two potentially important parameters on an upward-pointing OBS response to sediment accumulation measurements is investigated in a laboratory flume: (a) grain-size distribution and (b) bottom surface roughness in relation to water speed. Independent measurements of sediment accumulation were done with a specially built suction chamber. This chamber collects accumulated particles directly with a resolution of the order of 0.01 mg cm−2 and with an accuracy of 70%. The upward-pointing OBS response to sediment accumulation was found to vary (a) with grain size by less than 30% for a range of 15–1000 μm and (b) with water speed on a flat surface by less than 35% for a range of 0–7 cm s−1. Speed had no effect on the OBS response when a rough bottom surface was tested for a range of 0–3.5 cm s−1. This study contributes to the understanding of upward-pointing OBS to sediment accumulation, the only field technique to date able to provide high-resolution measurements of sediment accumulation, with a high temporal resolution but still over extended periods of time.
|Item Type:||Article (Refereed Research - C1)|
|Keywords:||backscatter; bottom surface roughness; particle size; sediment accumulation; water flow; sediment accumulation|
|Date Deposited:||16 Jun 2009 04:47|
|FoR Codes:||02 PHYSICAL SCIENCES > 0299 Other Physical Sciences > 029904 Synchrotrons; Accelerators; Instruments and Techniques @ 100%|
|SEO Codes:||96 ENVIRONMENT > 9611 Physical and Chemical Conditions of Water > 961102 Physical and Chemical Conditions of Water in Coastal and Estuarine Environments @ 100%|
|Citation Count from Web of Science||