Determination of suspended sediment concentration in the Grijalva-Usumacinta River System, Southern Gulf of Mexico

Abstract In this study, suspended sediment concentrations in the Grijalva-Usumacinta River System (GURS), southern Gulf of Mexico, were obtained using records of acoustic Doppler current profiler (ADCP) backscatter, current speed, and suspended solid concentrations (SSC) of water samples collected throughout a tidal cycle in October 2010 and September and November 2011. A model was obtained using linear regression statistical analysis to estimate the SSC using backscatter values. The results indicate that the estimated average concentrations of SSC were 0.13 g L −1 . The tidal regime governs the current velocities near the mouth of the river and the SSCs. The average flow of the Grijalva-Usumacinta River is 5136 m 3 s −1 , transporting a sediment load of 214.1 $$\times$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>×</mml:mo> </mml:math> 10 3 to 1467.2 $$\times$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>×</mml:mo> </mml:math> 10 3 m 3 month −1 . The sediment was predominantly silt and clay comprising terrigenous inorganic matter. A highly dynamic mouth bar is generated by suspended sediment transport.