Accession Number : ADA193979

Title :   Analysis of Sediment Transport in the Brazos River Diversion Channel Entrance Region.

Descriptive Note : Final rept. Aug 84-Feb 85,

Corporate Author : COASTAL ENGINEERING RESEARCH CENTER VICKSBURG MS

Personal Author(s) : Fields, M L ; Weishar, Lee L ; Clausner, James E

PDF Url : ADA193979

Report Date : May 1988

Pagination or Media Count : 138

Abstract : A combined office and field study was conducted to evaluate the feasibility of constructing a navigation channel in the Brazos River Diversion channel (BRDC). The evaluation was made through an analysis of existing data and a computation of shoaling rates. The office study consisted on an evaluation of the shoaling history of the area, which was determined through quantification of shoreline migration rates, and volumetric changes in the growth of the BRDC delta. Nearshore available longshore sediment transport quantities and rates were determined using Littoral Environment Observation (LEO) data. A two-dimensional (2-D) laterally averaged numerical model was used to predict sediment transport in the BRDC for the proposed channel dimensions. A second 2-D numerical-wave refraction/diffraction model was used to predict wave propagation over the Brazos River ebb-tide delta and adjacent regions. Field data utilized to run the numerical models consisted of water surface elevations, current velocities, salinities, suspended sediment concentrations, nearshore sediment samples, and bathymetric survey data. Considerations of the hydraulics in the lower BRDC suggest sediment transport occurs on a seasonal basis, resulting in periodic flushing and shoaling conditions. Shoaling rate calculations for the proposed channel dimensions of 12-ft deep by 125-ft wide, with 6-ft overdredging predict an annual maintenance dredging requirement of 735,000 cu yd, with an estimated project duration of approximately 4 months.

Descriptors :   *CHANNELS(WATERWAYS), *SEDIMENT TRANSPORT, BATHYMETRY, CHANNELS, CONCENTRATION(COMPOSITION), DREDGING, ELEVATION, ESTIMATES, FLUSHING, HISTORY, HYDRAULICS, INSHORE AREAS, LITTORAL ZONES, MAINTENANCE, MATHEMATICAL MODELS, MIGRATION, NAVIGATION, OBSERVATION, QUANTITY, RATES, REGIONS, REQUIREMENTS, SAMPLING, SEDIMENTS, SHORES, SURFACES, SURVEYS, SUSPENDED SEDIMENTS, TIME, VELOCITY, VOLUME, WATER, WAVE PROPAGATION, RIVERS, TEXAS, OCEAN WAVES, OCEAN TIDES, MEXICO GULF

Subject Categories : Civil Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE