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期刊论文 1

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2010 1

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Observation of bioturbation and hyporheic flux in streambeds

Jinxi SONG, Xunhong CHEN, Cheng CHENG,

《环境科学与工程前沿（英文）》 2010年 第4卷 第3期   页码 340-348 doi: 10.1007/s11783-010-0233-y

摘要： In the Elkhorn River, burrows, tubes, and sediment mounds created by invertebrate bioturbation were observed in the exposed streambed and commonly concentrated on the fine-sediment patches, which consist of silt, clay, and organic matter. These invertebrate activities could loosen the thin layer of clogging sediments and result in an increase of pore size in the sediments, leading to greater vertical hydraulic conductivity of the streambed (). The measurements of the vertical hydraulic gradient across the submerged streambed show that vertical flux in the hyporheic zone can alter directions (upward versus downward) for two locations only a few meters apart. In situ permeameter tests show that streambed in the upper sediment layer is much higher than that in the lower sediment layer, and the calculated in the submerged streambed is consistently greater than that in the clogged sediments around the shorelines of the sand bars. Moreover, a phenomenon of gas bubble release at the water-sediment interface from the subsurface sediments was observed in the groundwater seepage zone where flow velocity is extremely small. The bursting of gas bubbles can potentially break the thin clogging layer of sediments and enhance the vertical hydraulic conductivity of the streambed.

关键词： invertebrate bioturbation     clogging     hyporheic exchange     streambed     the Elkhorn River    

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Observation of bioturbation and hyporheic flux in streambeds

Jinxi SONG, Xunhong CHEN, Cheng CHENG,

期刊论文