This discussion paper is a preprint. A revision of the manuscript is under review for the journal Earth Surface Dynamics (ESurf).
Geomorphic implications of gravity currents created by changing initial conditions
Jessica Zordan1,Anton J. Schleiss1,and Mário J. Franca1,2Jessica Zordan et al. Jessica Zordan1,Anton J. Schleiss1,and Mário J. Franca1,2
1Laboratory of hydraulic constructions (LCH), School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
2River Basin Development chair group, Water Science and Engineering department, IHE Delft Institute for Water Education, 2611 Delft, the Netherlands
1Laboratory of hydraulic constructions (LCH), School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
2River Basin Development chair group, Water Science and Engineering department, IHE Delft Institute for Water Education, 2611 Delft, the Netherlands
Received: 09 Nov 2017 – Accepted for review: 13 Nov 2017 – Discussion started: 22 Nov 2017
Abstract. Gravity currents reproduced in laboratory by the lock-exchange technique are here tested for three initial densities and five lock-lengths, for horizontal and four inclinations of the lock. The main purpose is to quantify the effect of the increment of gravitational forces, due to the introduction of a slope, on the hydrodynamics of gravity currents and consequently on its transport capacity. The shape of the current is altered due to the enhanced entrainment of ambient water and mainly the body of the current results affected. A range of slopes is tested, going from horizontal to a limit case in which two mechanisms compete, i.e. the current entrainment of water from the upper surface due to the increment of friction and the head feeding by the rear steady current. In particular, bed shear stress and the corresponding geomorphic potential are analyzed. Using a base experience where erosion of a mobile bed was investigated, the implications of an inclined lock in the entrainment capacity of the flow is here discussed.