Hyperspectral data applied in monitoring and evaluating the water trophic state of Lake Chagan

An approach for monitoring and evaluating the trophic state with field reflectance spectra in Lake Chagan,China is presented. Based on in situ water sampling and measurements with ASD FieldSpec spectrometer, algorithms of Chlorophyll-a, Secchi Disk Depth (SDD) and TP have been developed. Furthermore, with the TSI_M trophic state index model, the trophic state of Lake Chagan was monitored and evaluated. The results showed that: (1)TSI_M model with hyperspectral datamay obtain accurate results; (2)Single parameter TSI_M compared with multi-parameter TSI_M is limited, which may induce false result; and (3)Lake Chagan was in eutrophic state, which needs to be prevented from further worsen.