In recent years, great amount of polluted water discharged into the north part of Lake TaiHu, results in water eutrophication and frequent occurrences of blue-green algal bloom in the area. In order to obtain the information about blue-green algal bloom distribution for monitoring water quality, four navigation of in situ hyperspectral measurement and MODIS data of 250 m resolution were used to study the radiance reflectance character and distribution of blue-green algal bloom in the lake. Hyperspectral measurement showed that the peak of water leaving radiance near 700 nm transferred to 750-780 nm as the water covered with blue-green algal bloom and increased with the increasing density of water bloom. Band ratio of channel I to channel II and band synthesize of MODIS image of 250 m resolution were used for detection of algal bloom, and proved that band ratio of channel I to channel II was more suitable for detection of algal bloom. The methods for differentiating submerged vegetation and algal bloom from MODIS image were also tested: The area covered with submerged vegetation usually had high secchi depth, with algal bloom usually low secchi depth, and the phenomena can be used efficiently for differentiating submerged vegetation and algal bloom on MODIS image.

Date Published: 20 October 2005
PDF: 8 pages
Proc. SPIE 5977, Remote Sensing of the Ocean, Sea Ice, and Large Water Regions 2005, 59770M (20 October 2005); doi: 10.1117/12.628065

Published in SPIE Proceedings Vol. 5977:
Remote Sensing of the Ocean, Sea Ice, and Large Water Regions 2005
Charles R. Bostater Jr.; Rosalia Santoleri, Editor(s)