Examining water quality in the Chesapeake Bay from space

Investigator: 
Micah Ziegler
Advisor: 
Patrick Vaccaro
Start Date: 
June, 2007
Description: 

I hope to continue working with sedimentation in the upper Chesapeake Bay and map the location of the estuarine turbidity maximum over a longer time period. Notably, I would like to see how the final data would look using the new V005 correction applied to the MODIS BRDF-adjusted reflectance L3 product. I would like to further investigate the potential of measuring water quality from space.

The Chesapeake Bay is the largest estuary in the United States and plays a critical ecological and economic role in the Mid-Atlantic Region. Sediment in the Bay increases turbidity, preventing light from reaching submerged aquatic vegetation, a crucial component of the ecosystem. In the upper bay, the Susquehanna River provides most of the sediment. Suspended sediment in the upper bay was studied using 23 tiles of 16-day composite MODIS reflectance images of the region compiled at even intervals during the 2006 calendar year. This project analyzes the ability of this the atmospherically and radiometrically corrected composite reflectance product to visualize temporal and spatial changes of suspended sediments over a variety of concentrations. The satellite data was compared and correlated against in situ measurements of secchi disk transparency and total suspended solids. Correlations between satellite data and water-based measurements were studied empirically and statistically. A good empirical relationship was found between in situ sediment levels and satellite observations in the red MODIS band. This band was then used to map the location and relative intensity of the northern Chesapeake’s estuarine turbidity maxima for 2006. Ideally, this procedure could be used to map the Bay’s sediments over a longer time span with better spatial resolution than is currently available in situ.