New trends in remote sensing for water resources management: hyperspectral remote sensing of water quality

Abstract

Remote Sensing techniques can be used to assess several water quality parameters (i.e., suspended sediments, chlorophyll, and total phosphorous). The optical and thermal sensors on boats, aircraft, and satellites provide both spatial and temporal information needed to understand changes in water quality parameters necessary for developing better management practices to improve water quality. With recent trends like hyperspectral remote sensing and planned launches of satellites with improved spectral and spatial resolution sensors, greater application of remote sensing techniques to assess and monitor water quality parameters will be possible. In June 2003 hyperspectral sensing in 96 bands in visible, near-infrared and thermal range was performed from a plane over the study area using a Compact Airborne Spectrographic Imager (CASI) sensor. Concurrently, water quality samples were collected directly from sampling points along Woluwe River on the same day as the flyovers. The samples were analysed for biological and chemical water qualities. Using correlations between ground-truth data and combinations of spectral bands from the remotely sensed data, spectral indices were developed which could be used to estimate water quality parameters. Maps of the relative distributions of chlorophyll a, totalfrom the hyperspectral images of the study area. phosphorous and secchi depth were created