Heterogeneity of hydraulic conductivity and Darcian flux in the submerged streambed and adjacent exposed stream bank of the Beiluo River, northwest China

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• 作者：Jinxi Song ; Weiwei Jiang ; Shaofeng Xu ; Guotao Zhang ; Liping Wang…
• 关键词：Hydraulic properties ; Vertical head gradient ; Streambed ; Groundwater/surface ; water relations ; China
• 刊名：Hydrogeology Journal
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：24
• 期：8
• 页码：2049-2062
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Hydrogeology; Hydrology/Water Resources; Geology; Water Quality/Water Pollution; Geophysics/Geodesy; Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution;
• 出版者：Springer Berlin Heidelberg
• ISSN：1435-0157
• 卷排序：24

文摘

Recognizing the heterogeneity of hydraulic conductivity and hyporheic flow is critical for understanding contaminant transfer and biogeochemical and hydrological processes involving streams and aquifers. In this study, the heterogeneity of hydraulic conductivity and Darcian flux in a submerged streambed and its adjacent exposed stream banks were investigated in the Beiluo River, northwest China. In the submerged streambed, Darcian flux was estimated by measurement of vertical hydraulic conductivity (K_v) and vertical head gradient (VHG) using in-situ permeameter tests. On exposed stream banks, both horizontal hydraulic conductivity (K_h) and K_v were measured by on-site permeameter tests. In the submerged streambed, K_v values gradually decreased with depth and the higher values were concentrated in the center and close to the erosional bank. Compared to the exposed stream banks, the K_v values were higher in the streambed. From stream stage to the topmost layer of tested sediment, through increasing elevation, the K_h values increased on the erosional bank, while they decreased on the depositional bank. The values of VHG along the thalweg illustrate that downwelling flux occurred in the deepest area while upwelling flux appeared in the other areas, which might result from the change of streambed elevation. The higher value of the Darcian flux in the submerged streambed existed near the erosional bank.