• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chinese science bulletin >Dynamics of sediment resuspension and the conceptual schema of nutrient release in the large shallow Lake Taihu, China
【24h】

Dynamics of sediment resuspension and the conceptual schema of nutrient release in the large shallow Lake Taihu, China

机译：太湖浅水区沉积物重悬动力学和养分释放概念图

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

On the basis of investigations in situ, it was found that mass exchange on the water-sediment interface occurred chiefly on the superficial sediment within 5-10 cm. The spatial physicochemical character of sediment was distributed uniformly. The observation of lake currents and waves indicated that the dynamic sources, which act on the interface of water and sediment, came mainly from waves under strong wind forcing, while the critical shear stresses due to the waves and currents were of the same magnitude under weak wind forcing. The critical shear stress that leads to extensive sediment re-suspension was about 0.03-0.04N/m~2, equivalent to a wind speed in situ up to 4 m/s. If a dynamic intensity exceeded the critical shear stress, such as a wind velocity up to 6.5 m/s, massive sediment re-suspension would be observed in the lake. Furthermore, field investigations revealed that the nutrient concentration of pore water within the sediment was far greater than that of overlaying water, which provides objective conditions for the nutrient release from sediment. According to nutrient analyses in the pore water from the superficial 5-10 cm sediments, a severe dynamic process in the Taihu Lake would bring out a peak nutrient release, i.e. a 0.12 mg/L increase of TN, and 0.005 mg/L increase of TP in the lake. In the end, a general scheme of nutrient release from sediment in large shallow lakes was put forward: when the wind-driven forcing imposes on the lake, it will make the sediment resuspension. At the same time, the nutrition from the pore water will follow the sediment resuspension release to overlaying water. Because of oxidation of solid particulates when it resuspends from sediment, the disturbance of hydrodynamics will enhance the suspension particulates absorbing nutrition. After the withdrawal of wind forcing, the suspended mass would deposit and bring part of the released nutrients back into sediment. The degraded organic particulate would he separated to the pore water within the sediment under the condition of deposition, and wait for the next wind forcing.
机译：在现场调查的基础上，发现水-沉积物界面的质量交换主要发生在5-10 cm的表层沉积物上。沉积物的空间理化特征分布均匀。湖泊水流和波浪的观测表明，作用于水和沉积物界面的动力源主要来自强风作用下的波浪，而在弱水作用下，波浪和水流引起的临界切应力大小相同。风强迫。导致沉积物大量悬浮的临界剪切应力约为0.03-0.04N / m〜2，相当于原位风速高达4 m / s。如果动态强度超过临界剪切应力（例如风速高达6.5 m / s），则会在湖中发现大量的沉积物重新悬浮。此外，野外调查表明，沉积物中孔隙水的养分浓度远高于上覆水，这为从沉积物中释放养分提供了客观条件。根据表层5-10 cm沉积物孔隙水中的养分分析，太湖中剧烈的动态过程会导致养分释放峰值，即TN增加0.12 mg / L，而TN增加0.005 mg / L。 TP在湖中。最后，提出了在大型浅水湖泊中从沉积物中释放养分的一般方案：当风强迫作用在湖泊上时，就会使沉积物重新悬浮。同时，来自孔隙水的营养将随着沉淀物的重悬而释放到上覆水。由于固体微粒从沉淀物中重新悬浮时会发生氧化，因此流体动力学的扰动会增强悬浮微粒吸收营养的能力。撤去风力后，悬浮物将沉积并将释放的部分养分带回沉积物中。在沉积条件下，降解的有机颗粒会分离到沉积物中的孔隙水中，并等待下一次强风。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号