Analysis of sediment resuspension in shallow lake under variable wind speed and water depth

Understanding wind-induced sediment resuspension is essential for predicting turbidity dynamics and nutrient cycling in shallow lakes. This study investigates the spatial variability of sediment resuspension under different hydrodynamic conditions and quantifies the influence of wind-driven forces on sediment stability. A controlled laboratory experiment was conducted using a wind-generation system comprising 13 rows of fans positioned at varying distances and angles with respect to three distinct regions (A, B, and C). Turbidity variations exhibited a strong linear correlation with the dimensionless parameter (W2/H) (R2 = 0.85–0.92), where W represents wind frequency (Hz) and H denotes water depth (m). This parameter effectively captures resuspension sensitivity. Further analysis showed that W, which reflects the proximity to the wind source, integrates the effects of both wind angle and position. Using the 50 NTU water quality threshold, critical (W2/H) values were determined as 2787, 7176, and 16,771 for regions A, B, and C, respectively—corresponding to wind frequencies of 17 Hz, 27 Hz, and 41 Hz at a depth of 0.1 m. Accordingly, regions B and C require approximately 1.6 and 2.5 times more wind energy than region A to reach the same turbidity level. These findings establish a quantitative relationship between wind-driven turbulence and sediment transport, providing insight into the spatial heterogeneity of sediment stability. This research offers both theoretical and practical implications for water quality management, including optimizing artificial aeration, mitigating eutrophication, and improving sediment regulation strategies in shallow lake ecosystems.