MONITORING EFFLUENT QUALITY IN HYPERTROPHIC WASTE-WATER RESERVOIRS USING REMOTE-SENSING

About one hundred and fifty wastewater reservoirs store effluents for irrigation in Israel. Effluent qualities differ according to the inflo wing wastewater quality, the degree of pretreatment and the operationa l parameters. Certain aspects of water quality like concentration of o rganic matter, suspended solids and chlorophyll are significantly corr elated with the water column transparency and colour. Accordingly opti cal images of the reservoirs obtained from the SPOT satellite demonstr ate pronounced differences correlated with the water quality. The anal ysis of satellite multispectral images is based on a theoretical model . The model calculates, using the radiation transfer equation, the vol ume reflectance of the water body. Satellite images of 99 reservoirs w ere analyzed in the chromacity space in order to classify them accordi ng to water quality. Principal Component Analysis backed by the theore tical model increases the method sensitivity. Further elaboration of t his approach will lead to the establishment of a time and cost effecti ve method for the routine monitoring of these hypertrophic wastewater reservoirs. Copyright (C) 1996 IAWQ. Published by Elsevier Science Ltd .