Monitoring Chlorophyll-A Concentration in New Jersey Lakes Using Remote Sensing and Ground Observations

The presence of Harmful Algal Blooms (HABs) occurs when colonies of cyanobacteria grow out of control and produce toxic or harmful effects on humans, fish and livestock. They are among most important factors that threaten water quality of lakes. The New Jersey Department of Environmental Protection (NJDEP) has been monitoring 800+ lakes since 2005. A possible alternative manner of monitoring the water's algae levels would be remote sensing from Landsat-8 and Sentinel-2 observations. Here, we utilized these observations and in situ data to examine the effectiveness of existing algorithms to find a regionally robust method that is applicable for NJ lakes. The methods consist of experimental equations that use several visible and near-infrared remote sensing data. Two selected methods were found generally able to predict Chl-a variations; however, they seem to have different performance accuracy when they are used for shallow and deep parts of the lakes. The results indicate the remote sensing observations could be used for monitoring lakes water quality.