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Abstract A field investigation was conducted of 61stations in Lake Taihu (summer, 2014). Based on the field measurements of several physical and chemical parameters, we first characterized the turbidity spatial and vertical distribution and analyzed its affecting factors. Then, water-sediment interface was identified using the measured vertical stratification of turbidity at the bottom in Lake Taihu. The results showed that the mean values of turbidity of surface, middle, and bottom layers were (28.3 ± 21.4), (23.0 ± 13.3), (31.7 ± 15.0) NTU, respectively. The maximum turbidity appeared in the northern regions of Lake Taihu, including Meiliang Bay and Gonghu Bay, followed by the southwestern open water. However, East Lake Taihu and Xukou Bay showed the lowest turbidity. The best predictor of turbidity of the surface, middle and bottom layers was the concentrations of chlorophyll a, inorganic suspended matter, and total suspended matter, respectively. The thickness of the water-sediment interface ranged from 45.0to 229.0mm with a mean value of (156.4 ± 53.5) mm. The higher thickness was observed in Gonghu Bay and southwestern open water. In contrast, the lower thickness appeared in East Lake Taihu and Xukou Bay. Significantly positive correlation was found between turbidity and the thickness of the water-sediment interface (R2=0.552). The study suggests that increasing turbidity frequently resulted from strong wind waves would increase the thickness of water-sediment interface. Therefore, the vertical stratification of turbidity can be used to quantitatively identify water-sediment interface thickness, which will provide scientific support for the study of nutrients exchange and material circulation between water-sediment interfaces.
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Received: 30 March 2015
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