H31G-1519
The effect of beach slope on tidal influenced saltwater intrusion

Wednesday, 16 December 2015
Poster Hall (Moscone South)
Zhongwei Zhao1, Chengji Shen2, Guangqiu Jin1, Pei Xin3, Guofen Hua3, Xiaohu Tao4 and Jian Zhao4, (1)Hohai University, Nanjing, China, (2)University of Queensland, School of Civil Engineering, St Lucia, Australia, (3)Hohai University, State Key Laboratory of Hydrology-Water Resources, Nanjing, China, (4)Hohai University, College of Water Conservancy and Hydropower Engineering, Nanjing, China
Abstract:
Beach slope changes the tidal induced saltwater-freshwater circulations in coastal aquifers. However, the effect of beach slope on tidal influenced saltwater-freshwater mixing process is far from understood. Based on sand flume experiments and numerical simulations, we investigated the intrusion process of saltwater into freshwater under tidal forcing and variable beach slopes. The sand flume experiment results show that milder slope induces larger upper saline plume (USP) and seaward salt wedge interface (SWI) under tidal forcing. While, the steady state SWI keeps stagnant with different beach slopes. Consistent with the previous research, our numerical simulations also show a lager flux exchange across the milder beach induced by the tidal fluctuations. The groundwater table fluctuates more intensify with deeper beach slope. The next step of our study will pay attention to the effect of beach slope on the instability of USP which induces the salt-fingering flow.