State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, People's Republic of China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Environ Sci Pollut Res Int. 2018 Dec;25(36):36341-36354. doi: 10.1007/s11356-018-3471-3. Epub 2018 Oct 27.
Wind-induced hydrodynamics are important forcing mechanisms of sediment resuspension in lakes. However, the relative contributions of wind-induced waves and currents on sediment resuspension during a wind event remain unclear. This study used high-frequency sensors to investigate the effects of wind waves, lake currents, and shear stress on sediment resuspension under different wind conditions (10 September to 17 October 2017) in Lake Taihu (China). Measurements showed that wind speed varied from 0.3 to 11.5 m/s, wave height varied from 0.035 to 0.46 m, lake current speed ranged from 0.001 to 0.39 m/s, and turbidity changed from 36.5 to 158.7 NTU. Sediment resuspension resulted primarily from wave- and current-induced shear stresses. Calculation showed these quantities varied in the range 0.045-0.338 and 0.002-0.127 N/m, respectively. Total shear stress showed positive correlation with turbidity. Wave-induced shear stress contributed more than 60% of the total. Waves and currents have different responses to wind. During periods of increasing turbidity, the percentage of wave-induced shear stress was initially high (> 85%) before decreasing with the development of the current. During periods of decreasing turbidity, the percentage of wave-derived shear stress declined initially before increasing with the decrease of current speed. The results showed a clear process regarding the contributions of shear stress from waves and currents during different stages of hydrodynamic development, which could be used to describe sediment resuspension in large shallow lakes that would help in the development of high-efficiency sediment resuspension models.
风致水动力是湖泊中泥沙再悬浮的重要动力机制。然而，风事件过程中波浪和水流对泥沙再悬浮的相对贡献仍不清楚。本研究使用高频传感器，于 2017 年 9 月 10 日至 10 月 17 日期间，在太湖（中国）不同风况下（风速 0.3-11.5m/s，波高 0.035-0.46m，湖流速度 0.001-0.39m/s，浊度 36.5-158.7NTU），调查风浪、湖流和切应力对泥沙再悬浮的影响。测量结果表明，风速变化范围为 0.3-11.5m/s，波高变化范围为 0.035-0.46m，湖流速度范围为 0.001-0.39m/s，浊度变化范围为 36.5-158.7NTU。泥沙再悬浮主要由波浪和水流引起的切应力引起。计算表明，这些量分别在 0.045-0.338 和 0.002-0.127N/m 的范围内变化。总切应力与浊度呈正相关。波浪引起的切应力贡献超过 60%。波浪和水流对风的响应不同。在浊度增加期间，波浪引起的切应力百分比最初较高（>85%），然后随着水流的发展而降低。在浊度降低期间，波浪产生的切应力百分比最初降低，然后随着水流速度的降低而增加。结果表明，在水动力发展的不同阶段，波浪和水流产生的切应力的贡献有一个清晰的过程，可以用来描述大型浅水湖泊的泥沙再悬浮，有助于开发高效的泥沙再悬浮模型。
