Medicion de la concentracion de sedimentos en suspension mediante dispositivos opticos y acusticos: aplicacion en sistemas tropicales (Delta del rio Mira, Colombia)

Abstract

In recent years, the use of optical (Optical Backscatter Sensor, OBS) and acoustic (Acoustic Current Doppler Profiler, ADCP) instruments has allowed monitoring the temporal and spatial variation of the suspended sediment concentration (SSC) in coastal and estuarine environments with greater resolution. However, the development of the application of those techniques in tropical environments is incipient. For this study, an OBS-3A calibration procedure was implemented, taking dry and desegregated sediment from the study zone as a calibrating pattern. Moreover, we present the corrections required for the ADCP signal to be useful in the estimation of SSC due to geometrical spreading, the attenuation of sound by water, and the particles in suspension. The ADCP and OBS-3A were used to measure SSC in the Mira River delta system (Morro Island and principal river mouth), located on the Pacific coast of Colombia, a coastal tropical environment where some oceanographic and estuarine factors determine the signal response of the instruments.