Satellite data and real time stations to improve water quality of Lake Manzalah

The objective of this study is to choose suitable approach for generating quantitative water quality products from Medium-Spectral Resolution Imaging Spectrometer (MERIS) imagery in near real-time. Four MERIS Case-II water processors included in the BEAM software package were studied for estimating the lake water quality. Chlorophyll-a (CHL), Turbidity (TUR) products of the BEAM processors were compared to in situ data. No statistically significant correlations were observed between in situ data and individual top-of-atmosphere (TOA) reflectances. By contrast, significant correlations were observed for the Band9/Band 7 ratio. Using uncorrected band ratios of TOA reflectances as input, coefficients of determination of 0.83 and 0.76 were obtained for TUR and CHL, respectively. The regression models for TUR and CHL were subsequently validated. The formulating regression models based on TOA reflectances is a valid approach to generate Earth Observation (EO) based water quality information in an operational setting. The results revealed that the empirical models estimated for TUR and CHL are more appropriate to generate water quality products from MERIS imagery.