Utilisation of Airborne Imaging Spectrometers for spectral Characterisation of Waste Waster Plumes
This study report on an investigation of the performance of high resolution imaging sensors in the field of water quality monitoring in coastal waters affected by industrial wastewater plumes. The aim is to develop methods for detection and identification of different kinds of water discharges and to make these methods applicable to the next generation satellite systems. In this work data from two imaging spectrometers have been evaluated and compared. The study areas are located at the northern part of the Swedish East Coast. Heavy industries with large amounts of industrial wastewater discharges, together with the outlets of several major Swedish rivers characterise this part of the Swedish coast. In situ measurements of chlorophyll -a, suspended matter and dissolved organic carbon are performed together with measurements of phosphorus, NOX and light absorption at 260 nm and 280 nm. Spectral profiles for sampling points and plume affected waters are extracted and analysed. Results from simple regression analysis show that best correlation are achieved for chlorophyll -a and suspended sediments, no significant correlation were found for dissolved organic carbon. It is shown that spectral difference between plume affected water and 'clean' water reaches its maximum between 650 and 700 nm for this data set. Further more it is shown that spectral variations between different plumes is greatest between 400 and 550 nm. Correlation was confirmed for chlorophyll and suspended sediments but correlation coefficients were weaker than expected.