Optical characteristics and factors that influence representative Lakes in the Taihu Lake basin, China

Abstract

From 2018 to 2019, a survey of a typical lakes system in the Taihu Lake basin, China, was carried out. To provide reference values for the restoration and management of submerged vegetation in the lakes, the optical attenuation coefficient (Kd) and euphotic depth (Zeu) of the water body were calculated, and the distribution characteristics and factors that influenced the underwater optical field lands with different nutrition levels in the basin were analyzed. The main factor affecting the distribution of photosynthetically active radiation (PAR) in lakes in the Taihu Lake basin is suspended solids (SS), dominated by inorganic suspended matter (ISS). Chlorophyll a (Chl-a), dissolved organic carbon (DOC), and chromophoric dissolved organic matter (CDOM) all affect, although weakly, the optical characteristics of lake wetlands. In CDOM, humic-like components have a more significant impact on Kd. The Kd of lakes in the Taihu Lake basin is closely related to permanganate index (CODMn) and especially total phosphorus (TP); The growth of aquatic vegetation is increased in Shanghu, Dianshan-Yuandang, Yangcheng, and Wuli Lakes that have higher Zeu and Zeu/Depth values.

Keywords

• Taihu Lake basin
• lake
• photosynthetically active radiation (PAR)
• nutrient salt