Surrogate Technologies for Monitoring Suspended‐Sediment Transport in Rivers

Measuring Suspended Sediment

“…Of the 261 suspended sediment samples collected during the 14 storm-runoff periods, 86% had SSC values larger than 50 000 mg l À1 (Nancy Hornewer, USGS, written communication, 2008). Similar to data collected at the Rio Caguitas in Puerto Rico and contrary to the aforementioned hypothesis, the Double Bubbler data collected at the Paria river at Lees Ferry streamgage seemed to have a large amount of signal noise, also making interpretation difficult (Gray and Gartner, 2010b). The Double Bubbler data were collected only during periods of elevated stages (water discharges) because the instrument was not fully submerged during normal shallow flows.…”

“…data needed to improve suspended sediment discharge computations in research settings and in limited operational deployments. Potentially useful instruments and methods for inferring the physical characteristics of fluvial sediments (Wren et al, 2000;Gartner et al, 2003;Bogen et al, 2003;Gray et al, 2003;Gray, 2003b;Gray and Glysson, 2004;Gray, 2005;Topping et al, 2007;Gray and Gartner, 2009, 2010a, 2010b, 2010c) are being developed and tested worldwide. For example, through the informal USGS Sediment Monitoring Instrument and Analysis Research Program (Gray, 2003a(Gray, , 2003bGray and Simõ es, 2008), the USGS and collaborators in other government agencies, academia, and the private sector are testing several instruments for measuring SSCs and, in some cases, PSDs.…”

“…An isokinetic, cable-suspended, streamlined version of the LISST-100X, the LISST-SL shown in Figure 13(b), features the capability of real-time velocity measurement. This measurement is, in turn, used to control a pump to withdraw a filament of water and route it through the laser beam at the ambient current velocity Gray and Gartner, 2004;Agrawal and Pottsmith, 2006;Gray and Gartner, 2009;. The performance of the LISST-SL has been evaluated by the Federal Interagency Sedimentation Project (2012) in a laboratory, a flume, and by USGS researchers in rivers in Washington and Illinois, USA.…”

“…Information on the field performance of the pressure-difference technology is available from USGS streamgages on the lower Río Caguitas in Puerto Rico (Larsen et al, 2001;Gray and Gartner, 2010b) and the Paria river in AZ, USA (Gray and Gartner, 2010b). Continuous pressure-difference data were collected during October-December 1999 at the Río Caguitas streamgage using a Double Bubbler, composed of a digital recorder, bubbler system, and two precision pressure sensors with orifices anchored at fixed depths in a vertical (Design Analysis Associates, Inc., 2008) ( Figure 15).…”

“…Deployment of the Double Bubbler in the Paria river was predicated on the hypothesis that Paria river SSCs, commonly exceeding peak measured Rio Caguitas SSCs by a factor of at least three and in some cases by 1-2 orders of magnitude, would subject the instrument to a substantially larger density range than that inferred for higher flows at the Rio Caguitas streamgage in Puerto Rico. However, even with the addition of a thermistor for monitoring water temperatures, results were inconclusive (Gray and Gartner, 2010b). Double Bubbler data were collected, at 5-min intervals, during periods of elevated flow at the Paria river streamgage from July 2004 through September 2006.…”