MONITORING SUSPENDED PARTICULATE MATTER IN PUERTO-RICO - FIELD-MEASUREMENTS AND REMOTE-SENSING

The spatial distribution of suspended particulate matter (SPM) was est imated in Mayaguez Bay on the west coast of Puerto Rico by using tradi tional ship board measurements and remotely sensed data acquired over four days during January 1990. This effort was part of a joint project between NASA and the University of Puerto Rico to develop techniques to monitor the water quality of a Caribbean coastal zone. This paper p resents the methods and algorithms developed to map and analyze short term changes in the source and spatial distribution of SPM in Mayaguez Bay by using remotely sensed data acquired by the Calibrated Airborne Multispectral Scanner (CAMS). A PC-based data acquisition system was developed to record continuous ship measurements of select in- water v ariables. Spectral reflectances derived from CAMS red and near-IR data were corrected for atmospheric effects and then used to generate maps of SPM. These maps displayed SPM plumes associated with the mouths of the bay's three river systems. Significant day-to-day differences in the spatial characteristics were observed, suggesting that changes in river discharge occurred. However, an analysis of estimated river disc harge, sediment yield, local wind field, and thermal river plume indic ates that observed sediment plumes result primarily from wind-driven r esuspension events.