Estimating sediment budgets at the interface between rivers and estuaries with application to the Sacramento‐San Joaquin River Delta

Where rivers encounter estuaries, a transition zone develops where riverine and tidal processes both affect sediment transport processes. One such transition zone is the Sacramento‐San Joaquin River Delta, a large, complex system where several rivers meet to form an estuary (San Francisco Bay). Herein we present the results of a detailed sediment budget for this river/estuary transitional system. The primary regional goal of the study was to measure sediment transport rates and pathways in the delta in support of ecosystem restoration efforts. In addition to achieving this regional goal, the study has produced general methods to collect, edit, and analyze (including error analysis) sediment transport data at the interface of rivers and estuaries. Estimating sediment budgets for these systems is difficult because of the mixed nature of riverine versus tidal transport processes, the different timescales of transport in fluvial and tidal environments, and the sheer complexity and size of systems such as the Sacramento‐San Joaquin River Delta. Sediment budgets also require error estimates in order to assess whether differences in inflows and outflows, which could be small compared to overall fluxes, are indeed distinguishable from zero. Over the 4 year period of this study, water years 1999‐2002, 6.6 ± 0.9 Mt of sediment entered the delta and 2.2 ± 0.7 Mt exited, resulting in 4.4 ± 1.1 Mt (67 ± 17%) of deposition. The estimated deposition rate corresponding to this mass of sediment compares favorably with measured inorganic sediment accumulation on vegetated wetlands in the delta.

[1]  H. P. Guy,et al.  Laboratory theory and methods for sediment analysis , 1969 .

[2]  George Porterfield,et al.  Computation of fluvial-sediment discharge , 1972 .

[3]  H. H. Carter,et al.  SUSPENDED SEDIMENT BUDGET FOR CHESAPEAKE BAY , 1977 .

[4]  George Porterfield,et al.  Sediment transport of streams tributary to San Francisco, San Pablo, and Suisun Bays, California, 1909-66 , 1980 .

[5]  John P. Downing,et al.  New instrumentation for the investigation of sediment suspension processes in the shallow marine environment , 1981 .

[6]  W. Kemp,et al.  A sediment budget for the Choptank River estuary in Maryland, U.S.A. , 1983 .

[7]  D. Eisma,et al.  Flocculation and de-flocculation of suspended matter in estuaries , 1986 .

[8]  G. D. Glysson,et al.  SEDIMENT-TRANSPORT CURVES , 1987 .

[9]  A. Decho,et al.  Microbial exopolymer secretions in ocean environments: their role(s) in food webs and marine processes , 1990 .

[10]  D. Helsel,et al.  Statistical methods in water resources , 2020, Techniques and Methods.

[11]  C. Conner,et al.  A laboratory investigation of particle size effects on an optical backscatterance sensor , 1992 .

[12]  Michael J. Carron,et al.  Chesapeake Bay Sediment Budget , 1992 .

[13]  D. Jay,et al.  “Downstream effects of water withdrawal in a small, high-gradient basin: Erosion and deposition on the Skokomish River delta” , 1994 .

[14]  Bay Area Wetlands Ecosystem Goals Project: Starting Considerations , 1995 .

[15]  D. Jay,et al.  Downstream effects of water withdrawal in a small, high-gradient basin: Erosion and deposition on the Skokomish River delta , 1996 .

[16]  T. K. Edwards,et al.  Field methods for measurement of fluvial sediment , 1998 .

[17]  Bruce E. Jaffe,et al.  Sedimentation and bathymetric change in San Pablo Bay, 1856-1983 , 1998 .

[18]  Shahadat Hossain,et al.  A Suspended Sediment Budget for the Modified Subtropical Brisbane River Estuary, Australia , 1998 .

[19]  J. Dupont,et al.  Hydrodynamics of suspended particulate matter in the tidal freshwater zone of a macrotidal estuary (the Seine Estuary, France) , 1999 .

[20]  B. Jaffe,et al.  Sedimentation and bathymetry changes in Suisun Bay: 1867-1990 , 1999 .

[21]  P. M. Lane,et al.  The calibration of optical backscatter sensors for suspended sediment of varying darkness levels , 2000 .

[22]  M.R. Simpson,et al.  Methods for accurate estimation of net discharge in a tidal channel , 2000, IEEE Journal of Oceanic Engineering.

[23]  C. Groat.  Field Methods for Measurement of Fluvial Sediment , 2001 .

[24]  B. Laignel,et al.  Morphosedimentary evolution of the macrotidal Seine estuary subjected to human impact , 2001 .

[25]  David H. Schoellhamer,et al.  Singular spectrum analysis for time series with missing data , 2001 .

[26]  E. Wolanski,et al.  Rapid, Human-Induced Siltation of the Macro-Tidal Ord River Estuary, Western Australia , 2001 .

[27]  Philip B. Williams,et al.  Physical Evolution of Restored Breached Levee Salt Marshes in the San Francisco Bay Estuary , 2002 .

[28]  D. Reed.  Understanding Tidal Marsh Sedimentation in the Sacramento-San Joaquin Delta, California , 2018, Journal of Coastal Research.

[29]  N. Ganju,et al.  Summary of suspended-sediment concentration data, San Francisco Bay, California, water year 2000 , 2002 .

[30]  J. Day,et al.  Response scenarios for the deltaic plain of the Rhône in the face of an acceleration in the rate of sea-level rise with special attention toSalicornia-type environments , 2002 .

[31]  B. Eyre,et al.  Suspended Sediment Exchange through the Sub-tropical Richmond River Estuary, Australia: a Balance Approach , 2002 .

[32]  Shi-lun Yang,et al.  Delta response to decline in sediment supply from the Yangtze River: evidence of the recent four decades and expectations for the next half-century , 2003 .

[33]  Continuous monitoring of suspended sediment discharge in rivers by use of optical backscatterance sensors , 2003 .

[34]  The fluxes and transformations of suspended particles, carbon and nitrogen in the Humber estuarine system (UK) from 1994 to 1996: results from an integrated observation and modelling study. , 2003, The Science of the total environment.

[35]  E. Wolanski,et al.  Water and fine sediment dynamics in transient river plumes in a small, reef-fringed bay, Guam , 2003 .

[36]  David H. Schoellhamer,et al.  Trends in the Sediment Yield of the Sacramento River, California, 1957 - 2001 , 2004 .

[37]  Catherine A. Ruhl,et al.  Computation of discharge using the index-velocity method in tidally affected areas , 2005 .

[38]  John R. Gray.  Proceedings of the Federal Interagency Sediment Monitoring Instrument and Analysis Research Workshop, September 9-11, 2003, Flagstaff, Arizona , 2005 .