2003. Hyperspectral remote sensing of water quality parameters for large rivers in the Ohio River basin

Optical indicators of water quality have the potential of enhancing the abilities of resource managers to monitor water bodies in a timely and cost-effective manner. However, the degree to which optical indicators are useful may depend on their applicability to data collected from multiple water bodies. In 1999, a Compact Airborne Spectrographic Imager (CASI) was flown over the relatively shallow Great Miami River (GMR), in Southwest Ohio, collecting hyperspectral bands of data. Concurrently, water quality samples and hand-held spectrometer data were collected directly from the river. Using correlations between the ground-truth data and combinations of spectral bands from the remotely sensed data, spectral indices were developed which could be used to estimate chlorophyll a, turbidity and phosphorus. In 2001, a similar study was conducted in which a CASI was flown over a portion of the Ohio River while ground-truth data were collected. These data were analyzed and tested against the spectral indices developed during the 1999 study. The GMR’s spectral index for chlorophyll a was applicable to the Ohio River data. However, slightly refined spectral indices for turbidity and phosphorus were required in this new environmental setting