Inverse Data Modelling for the Optical Properties of the Eutrophic Lake from Reflectance Spectra in Nanhu Lake of Changchun, China

Abstract

In this study, we present an inverse data modelling for the optical properties of the eutrophic water from reflectance spectra in Nanhu Lake of Changchun, China. The lake water in Nanhu Lake is optically dominated by scattering from suspended matter, whereas the lake water is dominated by absorption from phytoplankton (CHLa), total suspended matter (TSM), and coloured dissolved organic matter (CDOM or referred to as yellow substance). The main reason is that the Nanhu Lake is highly affected by the input from rivers and drainage systems from the area of Changchun, which discharge a high concentration of CDOM, nutrients, and mineral suspended solids. The reflectance spectra at 400–900 nm were measured in Nanhu Lake using the ASD-field spectroradiometer. An inverse data modelling was applied to analyse the optical properties of the eutrophic lake water. The result shows that the optical properties of the eutrophical water can be effectively modelled from reflectance spectra for the eutrophic lake. However, further studies are still needed to refine the method for determining the optical properties of eutrophic waters under study.