Experimental study on hyporheic flow varied by the clay lens and stream flow

• DOI: 10.1007/s12665-018-7668-z
• Publication Date: 2018-06-28T00:12:24Z
• Authors: Chengpeng Lu; Wei Zhuang; Suwan Wang; Xuanyu Zhu; Huimin Li
• Keywords: Hyporheic Zone; Flow conditions; Infiltration (HVAC)

Hyporheic exchange is one of the important physical processes that affect the flow condition of surface water–groundwater interaction zone, the restoration of water environment and the maintenance of ecological balance. The influence mechanism of clay lens on hyporheic exchange has not been well revealed by now. A two-dimensional sand tank was constructed to study the influence of low permeable clay lens on the hyporheic zone under different surface flow conditions. Experimental results showed that the influence of clay lens on the hyporheic zone was of direction dependent and influenced by the size and location of clay lens and stream flow. The influence of clay lens on hyporheic exchange is not only hindering, but also enhancement at certain conditions. With the increase of the depth of clay lens, the hyporheic flow affected by clay lens show three patterns: inhibition, enhancement, and stability. Moreover, these effects were gradually weakened with the increase of stream flow. Hyporheic flow around the clay lens was more sensitive while the surface flow is at a relative small rate. The increasing of the clay lens length weakened the infiltration of surface water and the upwelling of groundwater. The joint action of surface water and groundwater is one of the important control conditions, and that will affect the clay lens to change the hyporheic exchange significantly.