It is important to remember the bottom
Ann Arbor, MI — Great Lake ecosystem dynamics require large scale tools for their analysis and monitoring. Remote sensing provides an important tool for scientists and lake managers. These tools allow an extensive analysis over hundreds of square kilometers of lake environment, giving us key information about water quality and biological conditions. However, in the large shallow lakes of southeast China, major complications in the use of these approaches is caused by the shallowness of the lakes studied. When optical satellite sensors read signals which originate from the lake bottom, it becomes difficult to separate water quality measurements from sediment quality measurements. Therefore it becomes important to separate optically shallow waters where sediment and submerged vegetation may influence remotely measured observations from optically deep waters where measurements are influenced only by the water quality of the water column. We show how these approaches are used in one of the most important lakes in China, Taihu Lake, where major algal blooms compromise the water supply for millions of persons who depend on the lake. We show how a significant improvement in the predictive capacity of the reflectance based estimates of phytoplankton biomass was made when areas with bottom influences were removed from calibration procedures.
Original Publication Information
Results of this study, "Approximate bottom contribution to remote sensing reflectance in Taihu Lake, China," are reported by Ronghua Ma, Hongtao Duan, Qinhuo Liu, and Steven Arthur Loiselle in the latest issue (Volume 37, No. 1, pp. 18-25) of the Journal of Great Lakes Research, published by Elsevier, 2011.
Contacts
For more information about the study, contact Ronghua Ma, mrhua2002@niglas.ac.cn, or Hongtao Duan, htduan@niglas.ac.cn.
For information about the Journal of Great Lakes Research, contact Marlene Evans, Editor, National Water Research Institute, Environment Canada, 11 Innovation Boulevard, Saskatoon, SK, S7N 3H5, Canada; jglr@ec.gc.ca; (306) 975-5310.
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