The preliminary inquiry of Chlorophyll-a inversion algorihtms applicable to guanting reservoir

Chlorophyll-a is an important index of entrophication. A large number of scholars have engaged in studying Chl-a inversion methodologies in the heavily polluted case II waters. However, the low-level-polluted case II waters haven´t been paid enough attentions. In this study, we chose Guanting Reservoir, China, a low-level-polluted case II water area, as our study field. Then, we modeled three algorithms (original three-band algorithm, enhanced three-band algorithm and analytical algorithm) to retrieve Chl-a concentration. The results show that the Chl-a concentration predicted by the enhanced three-band algorithm is much more correlated with the measured Chl-a concentration (R2=0.843, RMSE=1.98) than the original three-band algorithm (R2=0.802, RMSE=2.15) and analytical algorithm (R2=0.836, RMSE=2.24). So, the enhanced three-band algorithm is the most applicable method of these three algorithms and has the potential applied in the inversion of Chl-a concentration in low-level-polluted case II waters.