caa a22 4500 445299401 CHVBK 20180317142552.0 cr unu---uuuuu 170323e20100101xx s 000 0 eng 10.1007/s11430-009-0185-x doi (NATIONALLICENCE)springer-10.1007/s11430-009-0185-x Numerically quantifying the relative importance of topography and buoyancy in driving groundwater flow [Elektronische Daten] [JianWen Yang, ZuoHai Feng, XianRong Luo, YuanRong Chen] Both topography and buoyancy can drive groundwater flow; however, the interactions between them are still poorly understood. In this paper, the authors conduct numerical simulations of variable-density fluid flow and heat transport to quantify their relative importance. The finite element modeling experiments on a 2-D conceptual model reveal that the pattern of groundwater flow depends largely upon the relative magnitude of the flow rate due to topography alone and the flow rate due to buoyancy alone. When fluid velocity due to topography is greater than that due to buoyancy at large water table gradients, topography-driven ‘forced convection' overwhelms buoyancy-driven ‘free convection'. When flow velocity due to buoyancy is greater than that due to topography at small water table gradients, mixed free and forced convection takes place. In this case, free convection becomes dominant, but topography-driven flow still plays an important role since it pushes the free convection cells to migrate laterally in the downhill direction. Consequently, hydrothermal fluid flow remains changing periodically with time and no steady state can be reached. The presence of a low-permeability layer near the surface helps eliminate the topography effect on the underlying free convection. Science in China Press and Springer Berlin Heidelberg, 2010 hydrothermal flow nationallicence free convection nationallicence forced convection nationallicence topography nationallicence buoyancy nationallicence finite element modeling nationallicence Yang JianWen Faculty of Earth Sciences, Guilin University of Technology, 541004, Guilin, China aut Feng ZuoHai Faculty of Earth Sciences, Guilin University of Technology, 541004, Guilin, China aut Luo XianRong Faculty of Earth Sciences, Guilin University of Technology, 541004, Guilin, China aut Chen YuanRong Faculty of Earth Sciences, Guilin University of Technology, 541004, Guilin, China aut Science in China Series D: Earth Sciences SP Science in China Press 53/1(2010-01-01), 64-71 1674-7313 53:1<64 2010 53 11430 https://doi.org/10.1007/s11430-009-0185-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11430-009-0185-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yang JianWen Faculty of Earth Sciences, Guilin University of Technology, 541004, Guilin, China aut NATIONALLICENCE 700 1- Feng ZuoHai Faculty of Earth Sciences, Guilin University of Technology, 541004, Guilin, China aut NATIONALLICENCE 700 1- Luo XianRong Faculty of Earth Sciences, Guilin University of Technology, 541004, Guilin, China aut NATIONALLICENCE 700 1- Chen YuanRong Faculty of Earth Sciences, Guilin University of Technology, 541004, Guilin, China aut NATIONALLICENCE 773 0- Science in China Series D: Earth Sciences SP Science in China Press 53/1(2010-01-01), 64-71 1674-7313 53:1<64 2010 53 11430 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer