引用本文: | 李一平,王建威,姜龙,唐春燕,杜薇,罗潋葱,戴淑君.浅水湖泊动力作用下水-土界面底泥起悬驱动力野外观测.湖泊科学,2017,29(1):43-51. DOI:10.18307/2017.0105 |
| LI Yiping,WANG Jianwei,JIANG Long,TANG Chunyan,DU Wei,LUO Liancong,DAI Shujun.The driving force of sediment suspension on sediment-water interface in shallow lakes. J. Lake Sci.2017,29(1):43-51. DOI:10.18307/2017.0105 |
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浅水湖泊动力作用下水-土界面底泥起悬驱动力野外观测 |
李一平1,2, 王建威1, 姜龙1, 唐春燕3, 杜薇1, 罗潋葱4, 戴淑君4
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1.河海大学环境学院, 南京 210098;2.河海大学浅水湖泊综合治理与资源开发教育部重点实验室, 南京 210098;3.新加坡南洋理工大学南洋环境与水源研究院环境模拟中心, 新加坡 637457;4.中国科学院南京地理与湖泊研究所, 南京 210008
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摘要: |
动力扰动引起的水-土界面沉积物悬浮是浅水湖泊蓝藻水华控制的难点,本文基于声学高频流速仪、浊度仪、气象、波浪等观测仪器获取的高时空分辨时间序列参量,以太湖为例对动力扰动下的底泥起悬驱动力进行研究.结果表明风速小于3 m/s时,水-土界面处平均悬浮物浓度为59 mg/L,波流综合切应力小于0.015 N/m2,底泥未起悬或在底床附近极小范围内发生起悬;风速在3~6 m/s时,水-土界面处平均悬浮物浓度为103 mg/L,波浪产生的底切应力大部分情况远大于湖流产生的切应力,波流综合切应力处于0.015~0.25 N/m2范围内,底泥中等规模起悬;风速大于6 m/s时,水-土界面处平均悬浮物浓度为174 mg/L,波浪产生的底切应力占据绝对的主导地位,波流综合切应力大于0.25 N/m2,底泥大规模起悬.梅梁湾底泥起悬的临界切应力在0.015 N/m2左右,临界风速大约为3 m/s. |
关键词: 水-土界面 风 底泥起悬 切应力 太湖 悬浮物浓度 |
DOI:10.18307/2017.0105 |
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基金项目:国家自然科学基金项目(51579071,51379061)、中央高校基本科研业务项目基金项目(2014B07314)和江苏省高校优势学科建设工程项目联合资助. |
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The driving force of sediment suspension on sediment-water interface in shallow lakes |
LI Yiping1,2, WANG Jianwei1, JIANG Long1, TANG Chunyan3, DU Wei1, LUO Liancong4, DAI Shujun4
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1.College of Environment, Hohai University, Nanjing 210098, P. R. China;2.Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, P. R. China;3.Environmental Process Modelling Centre, Nanyang Environmental and Water Research Institute, Nanyang Technological University, 637457, Singapore;4.Nanjing Institute of Geography and Liminology, Chinese Academy of Sciences, Nanjing 210008, P. R. China
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Abstract: |
Sediment suspension on sediment-water interface caused by dynamic disturbance is the difficult issue in shallow lake eutrophication control. To study the driving force of sediment suspension in Meiliang Bay of Lake Taihu, a set of synchronous, high-frequency data of current, turbidity, wind, wave are obtained using the Acoustic Doppler Velocimeter, Optical Backscatter Sensor, PH-Ⅱ Handheld weather stations, and RBRduo T.D. wave tide gauge. The results show that when the wind speed is less than 3 m/s, the average suspended solid concentration (SSC) on sediment-water interface is approximately 59 mg/L. The bottom shear stresses generated by waves is nearly equal to that generated by currents, where no sediment suspension can be found and the comprehensive shear stress generated by wind-induced waves and currents is less than 0.015 N/m2. When the wind speed ranges from 3 to 6 m/s, the average SSC on sediment-water interface is approximately 103 mg/L. The bottom shear stresses generated by waves is greater than that generated by currents in most cases, where a medium amount of sediment is suspended and the comprehensive shear stress generated by wind-induced waves and currents ranges from 0.015 to 0.25 N/m2. When the wind speed exceeds 6 m/s and the average SSC on sediment-water interface is approximately 174 mg/L, the wave-generated shear stress plays an absolute leading role in large amount of sediment suspension and the comprehensive shear stress generated by wind-induced waves and currents is larger than 0.25 N/m2. The critical shear stress of sediment suspension in Meiliang Bay is approximately 0.015 N/m2 while the critical wind speed is 3 m/s. |
Key words: Sediment-water interface wind bottom sediment suspension shear stress Lake Taihu suspended solid concentration |
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