Surface Water Quality Monitoring Using Remote Sensing

Abstract

This paper describes the possibility of surface water quality monitoring using remote sensing technology and the spectral signatures of pure water and other types of water quality. Using airborne and spaceborne data (TM and ERS\|2) analysed with in situ measurements of ground truth points for water quality parameters, some major factors of surface water quality can be derived from remote sensing data by case studies. Concurrent in situ surface water quality measurments, Landsat TM data and ERS\|2 SAR data were obtained in the selected locations in August1997. In situ data included measurements of chlorophyll\|a, total dissolved organic carbon and turbidity, Secchi disk depth, color index, estimated wave height, salinity and surface temperature. The Landsat TM and ERS\|2 SAR data from locations of water samples were extracted and the digital data were examined in their raw states as well as numerous transformations. Significant correlations were observed between digital numbers and surface water quality parameters. The results indicate that it may be possible to derive surface water quality parameters using remote sensing data in our case study area. However, the technique still needs to be refined to detect differences within the range of water quality which is typically found in the area under study.