title: A quantitative analysis of hydraulic interaction processes in stream-aquifer systems.
abstract: The hydraulic relationship between the stream and aquifer can be altered from hydraulic connection to disconnection when the pumping rate exceeds the maximum seepage flux of the streambed. This study proposes to quantitatively analyze the physical processes of stream-aquifer systems from connection to disconnection. A free water table equation is adopted to clarify under what conditions a stream starts to separate hydraulically from an aquifer. Both the theoretical analysis and laboratory tests have demonstrated that the hydraulic connectedness of the stream-aquifer system can reach a critical disconnection state when the horizontal hydraulic gradient at the free water surface is equal to zero and the vertical is equal to 1. A boundary-value problem for movement of the critical point of disconnection is established for an analytical solution of the inverted water table movement beneath the stream. The result indicates that the maximum distance or thickness of the inverted water table is equal to the water depth in the stream, and at a steady state of disconnection, the maximum hydraulic gradient at the streambed center is 2. This study helps us to understand the hydraulic phenomena of water flow near streams and accurately assess surface water and groundwater resources.
authors.affiliation: Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xian, 710054, P.R. China.
authors.forename: Wenke
authors.initials: W
authors.lastname: Wang
authors.affiliation: Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
authors.forename: Zhenxue
authors.initials: Z
authors.lastname: Dai
authors.affiliation: Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xian, 710054, P.R. China.|UCD Dooge Centre for Water Resources Research, School of Civil, Structural and Environmental Engineering, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Yaqian
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xian, 710054, P.R. China.
authors.forename: Junting
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xian, 710054, P.R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Duan
authors.affiliation: Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xian, 710054, P.R. China.
authors.forename: Zhoufeng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Resources Environment and Tourism, Capital Normal University, Beijing 100048, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhu
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