Journal de télédétection et SIG

Abstrait

Application of Landsat 8 Aquatic Reflectance Band Data to Analyze Variations in Chlorophyll a, Suspended Sediment, N, and P in Coastal Estuaries of Southern Louisiana

Christopher Potter

Nutrient enrichment of estuaries is a proven causal agent of harmful algal blooms, fish kills, and hypoxic zones. To enable regional mapping in coastal estuaries of southern Louisiana of Chlorophyll a (Chl-a), suspended sediment, Nitrogen and Phosphorus (N and P) concentrations, monthly water sample data collected at over 30 stations along a 129 km transect in the Barataria Basin were correlated with Landsat 8 Aquatic Reflectance (AR) Band 4 (Red) image data acquired from 2013 to 2016. Analysis showed significant non-linear correlations of Landsat Aquatic Reflectance (AR) Band 4 values with measured concentrations of Chlorophyll a, total suspended sediment, N, and P. The strongest correlations were revealed between Landsat AR Band 4 reflectances and total P concentrations, periodically at R² values >0.6. Landsat AR band images revealed detailed variations in total N and P concentrations that were consistent with the measured nutrient declines associated with dilution of freshwater as sampling locations progressed toward more coastal saline waters.