Retrieval of Chlorophyll-a and suspended matter concentration in water supply sources of Wuxi and Suzhou using multi-spectral remote sensing images

摘要

The problem of water source pollution has become more and more serious in Wuxi and Suzhou district. It is urgent to monitor water quality widely and rapidly, which is the advantage of remote sensing. However, water sources around cities are inland waters in which chlorophyll-a and suspended matter concentrations are hard to be retrieved accurately from remote sensing just by using empirical methods. To overcome this problem, this study has developed an analytical method based on inherent optical parameters to retrieve chlorophyll-a and suspended matter concentrations. To validate this method, we have collected a dataset as follows: CBERS CCD image in Taihu Lake around Wuxi and Suzhou, in-situ measured water reflectance spectra, and inherent optical parameters, and the simultaneously measured aerosol data from Wuxi. Based on two approximate premises, we apply the red and the near infrared images to get total suspended matter concentration and chlorophyll-a concentration. The retrieved concentrations of total suspended matter and chlorophyll-a are close with in-situ measured ones. This study is helpful for monitoring water quality of water supply sources from multi-spectral remote sensing images.