AbstractA data set was acquired on a shallow mudflat in south San Francisco Bay that featured simultaneous, co-located optical and acoustic sensors for subsequent estimation of suspended sediment concentrations (SSC). The optical turbidity sensor output was converted to SSC via an empirical relation derived at a nearby site using bottle sample estimates of SSC. The acoustic data was obtained using an acoustic Doppler velocimeter. Backscatter and noise were combined to develop another empirical relation between the optical estimates of SSC and the relative backscatter from the acoustic velocimeter. The optical and acoustic approaches both reproduced similar general trends in the data and have merit. Some seasonal variation in the dataset was evident, with the two methods differing by greater or lesser amounts depending on which portion of the record was examined. It is hypothesized that this is the result of flocculation, affecting the two signals by different degrees, and that the significance or mechanism of the flocculation has some seasonal variability. In the earlier portion of the record (March), there is a clear difference that appears in the acoustic approach between ebb and flood periods, and this is not evident later in the record (May). The acoustic method has promise but it appears that characteristics of flocs that form and break apart may need to be accounted for to improve the power of the method. This may also be true of the optical method: both methods involve assuming that the sediment characteristics (size, size distribution, and shape) are constant
Alvarez, L. G., and S. E. Jones. 2002. Factors influencing suspended sediment flux in the upper Gulf of California. Coastal and Shelf Sci, 54:747-759.
Buchanan, P.A., and T.L. Morgan. 2012. Summary of suspended-sediment concentration data, San Francisco Bay, California, Water Year 2009: U.S. Geological Survey Data Series 744, 26 p.
Buchanan, P.A., and T.L. Morgan. 2014. Summary of suspended-sediment concentration data, San Francisco Bay, California, Water Year 2010: U.S. Geological Survey Data Series 808, 30 p., DOI: http://dx.doi.org/10.3133/ds808.
Conomos, T.J. 1963. Geologic aspects of the recent sediments of South San Francisco Bay, Master of Science Thesis, San Jose State College, San Jose, CA, USA, 118 pp.
Conomos, T.J., R.E. Smith, and J.W. Gartner. 1985. Environmental setting of San Francisco Bay. Hydrobiologia, 129, 1 -12.
Elci, Ş., R. Aydın, and P.A. Work. 2009. Estimation of suspended sediment concentration in rivers using acoustic methods. Environ Monit Assess, 159, 255-265.
Gartner, J.W. 2004. Estimating suspended solids concentrations from backscatter intensity measured by acoustic Doppler current profiler in San Francisco Bay, California. Mar Geol, 211(3), 169-187.
Hamilton, L.J., Z. Shi, and S.Y. Zhang. 1998. Acoustic backscatter measurements of estuarine suspended cohesive sediment concentration profiles. J Coastal Res, 14(4), 1213-1224.
Hay, A.E. 1991. Sound scattering from a particle-laden turbulent jet. J Acoust Soc Am, 90, 2055-2074.
Hay, A.E. and J. Sheng. 1992. Vertical profiles of suspended sand concentration and size from multi-frequency acoustic backscatter. J Geophys Res, 97(C10), 15661-15677.
Hosseini, S.A., A. Shamsai, and B. Ataie-Astiani. 2005. Synchronous measurements of the velocity and concentration in low density turbidity currents using an acoustic Doppler velocimeter. Flow Meas Instrum, 17, 59-68.
Jaffe, B., A. Foxgrover, and D. Finlayson. 2011. Mudflat loss during South San Francisco Bay salt pond restoration: regional and global perspectives on initial post-restoration changes. South Bay Science Symposium, CA, USA.
Knebel, H.J., T.J. Conomos, and J.A. Commeau. 1977. Clay-mineral variability in the suspended sediments of the San Francisco Bay system, California. Journal of Sedimentary Petrology, 47,229-236.
Landers, M.N., T.D. Straub, M.S. Wood, and M.M. Domanski. 2016, Sediment acoustic index method for computing continuous suspended-sediment concentrations: U.S. Geological Survey Techniques and Methods, book 3, chap. C5, 63 p., http://dx.doi.org/10.3133/tm3C5.
MacDonald, I.T., C.E. Vincent, P.D. Thorne, and P.D. Moate. 2013. Acoustic scattering from a suspension of flocculated sediments. J Geophys Res, Oceans, 118, 1-14.
Porterfield, G. 1980. Sediment transport of streams tributary to San Francisco, San Pablo, and Suisun Bays, California, 1909-1966. U.S. Geological Survey Water Resources Investigations 80-64.
Schulkin, M., and H.W. Marsh. 1962. Sound absorption in sea water. Journal of the Acoustical Society of America, 34(6), 864- 865.
Shellenbarger, G.G., S.A. Wright, and D.H. Schoellhamer. 2013. A sediment budget for the southern reach in San Francisco Bay, CA: implications for habitat restoration. Mar Geo, 345:281-293.
SonTek. 1998. Doppler current meters: Using signal strength to monitor suspended sediment concentration. Technical Note, SonTek Inc., San Diego, CA, USA.
Thevenot, M.M., T.L. Prickett, and N.C. Kraus. 1992. Tylers Beach, Virginia, dredged material plume monitoring project, 27 September to 4 October 1991. Dredging Research Program Technical Report DRP-92-7, US Army Corps of Engineers, Washington, DC, 204 pp.
Thorne, P.D. and P.J. Hardcastle. 1997. Acoustic measurements of suspended sediments in turbulent currents and comparison with in-situ samples. J Acoust Soc Am, 101, 2603-2614.
Thorne, P.D., and D.M. Hanes. 2002. A review of acoustic measurement of small-scale sediment processes. Cont Shelf Res, 22(4), 603-632.
Urick, R.J. 1948. The absorption of sound in suspensions of irregular particles, J. Acoust. Soc. Am., 20(3), 283-289.
Urick, R.J. 1975. Principles of Underwater Sound. McGraw-Hill Inc., New York, US.
Wright, S.A., and D.H. Schoellhamer. 2004. Trends in the sediment yield of the Sacramento River, California, 1957-2001. San Francisco Estuary and Watershed Science, 2. http://repositories. cdlib.org/jmie/sfews/vol2/iss2/art2.
Xavier, B.C, C.P. Ribeiro, L.G. Guimaraes,, M.G. Gallo, and A.G. Figueiredo, Jr. 2015. Estimation of suspended sediment concentration by acoustic calibration and scattering properties: an experimental and theoretical analysis. IEEE/OES Acoustics in Underwater Geosciences Symposium, Rio de Janeiro, Brasil, July 29-31.