Using Remotely Sensed Images to Evaluate Suspended Sediment Transport and Biologic Productivity in Galveston Bay

Historically, various methods have been used to measure total suspended sediment concentrations, including point sampling and filtration along with secchi disk transparency readings and turbidity probes. To obtain a synoptic view of the bay requires that a representative number of samples of appropriate spatial distribution be collected over a sufficiently long time frame. This approach is prohibitive in terms of both time and money in such a large water body as Galveston Bay. To overcome the problems inherent in comprehensive sampling in a large, variable water body, this study uses remotely sensed data platforms correlated with a short-term, intensive water quality sampling program to evaluate total suspended sediment concentrations and primary productivity (chlorophyll a) in the Galveston Bay complex. Since the values recorded by remotely sensed images are measurements of reflectance in given wavelengths rather than direct measurement of the parameter of interest, ground truth data must be acquired to correlate the reflectance value to the parameter. Once this correlation has been established, however, remotely sensed images can be used to monitor changes in that parameter without the need for future ground truth.