Correlations Between Reflectance Spectra and Contents of Chlorophyll-a in Chaohu Lake
LI SujuWU QianWANG XuejunPIAO XiuyingDAI Yongning (Key Laboratory for Surface Processes, Ministry of Education; Department of Urban and Environment Sciences, Peking University, Beijing 100871,P. R. China)
Chaohu Lake is one of the biggest freshwater lakes of China. This study was conducted to establish correlations between reflectance spectra and contents of chlorophyll a in Chaohu Lake, which was in eutrophic status. Reflectance spectra were measured during November, 2001 by using ASD FieldSpec HandHeld radiometer. Water samples for chlorophyll a measurements and dominant algal species determination were collected at the same time. The features of the spectral reflectance of the lake were discussed. The correlation between the spectral reflectance of single band and the content of chlorophyll a was low. The reflectance ratio of R 705nm / R 680nm and the reflectance first derivative of 690nm were found to be significantly correlated with the contents of chlorophyll a, and the r 2 gained using the reflectance ratio was higher than gained from the reflectance first derivative of 690nm's.