Abstract
The objective of this study is to validate the method of chlorophyll-a (Chla) estimation in the brackish Lake Tougou-ike which is located in the central part of Tottori Prefecture. The 42 (4 times) in-situ spectral reflectance / Chla data set was acquired from May, 2013 to July, 2015 for the validation. As a result, a substantial margin of error at the high Chla area of more than 40 μgL-1 was observed using "Koyama-ike model" using 2 bands of 672nm and 704nm. A new three band model based on bio-optical theory in the water was adopted and an optimal expression and suitable bands for this lake were discussed to reduce the error. Finally the Chla estimation model using 3 band model of 650nm, 703nm, and 740nm substantially improved the precision of about 8% compared with Lake Koyama-ike model.
