Explicit Consideration of Preferential Submarine Groundwater Discharges as Seawater Intrusion Control Measures
Abstract
Seawater intrusion is a global problem for coastal aquifers. Aquifer over-exploitation and climate change have further complicated the scenario. Submarine groundwater discharge (SGD) is controlled by groundwater hydraulic gradients in aquifer. The SGD mechanism depends on several parameters such as hydraulic gradient, tidal range, and position of freshwater-saltwater interface change over time. Sensor based measurement method can be used for the transient changes in vertical differential fluid pressures. Multiple approaches are available for understanding the effects of seawater intrusion mechanism and the flow dynamics within the homogeneous porous media.
The present work focuses on two-dimensional experimental setup for simulating the density-driven convection to SGD. Density dependent flow movements through tracer movement are analyzed by using image analysis. The angle of image analysis revealed the SGD flow rates and control measures for saltwater intrusion. Time-variable salinity and equivalent freshwater head boundary conditions at the freshwater have significant impacts on seawater-freshwater interaction. Experimental results show that preferential flow path (inland to seaward) exists in presence of SGD. SGD creates re-circulation zone in porous media. The recirculated flow in SGD and length of the re-circulation zone vary for different geo-hydrological conditions.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.H33T2346D
- Keywords:
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- 1829 Groundwater hydrology;
- HYDROLOGYDE: 1847 Modeling;
- HYDROLOGYDE: 1859 Rocks: physical properties;
- HYDROLOGYDE: 1875 Vadose zone;
- HYDROLOGY