Impact of bottom slope angles in sand tank model on seawater intrusion in confined aquifers
In coastal regions,there is a widespread presence of confined aquifers sloping seaward,but the impact of the aquitard's bottom slope angle on seawater intrusion remains unclear.In this paper,laboratory sandbox experiments employing color tracing technology were first conducted to analyze the dynamic process of seawater intrusion into confined aquifers under various bottom slope angles.The impact characteristics of sea level height,the amount of subterranean freshwater discharge,and aquifer lithology on seawater intrusion into seaward sloping confined aquifers were then investigated.The results demonstrate that the bottom slope angles significantly affects seawater intrusion into confined aquifers.When the interface between saline and freshwater during seawater intrusion stabilizes,there exists an exponential function relationship between the bottom slope angle and the length of the saltwater wedge:the length of the saltwater wedge decreases as the slope angle increases.Under constant head conditions,the discharge of subterranean freshwater decreases with the increase of the bottom slope angle.Under constant flow boundary conditions,although changes in bottom slope angles have no impact on subterranean freshwater discharge,the area of the saltwater wedge consistently decreases with an increase of the slope angle.When the lithology changes from coarse sand to fine sand in inclined aquifer,the length of saltwater wedge shortens as the hydraulic conductivity of the aquifer decreases,and the shortening becomes the greatest under constant-flow conditions.For confined aquifers sloping seaward,the smaller the bottom slope angle is,the greater the impact of sea level rise and subterranean freshwater discharge on the degree of seawater intrusion becomes.
万方数据
维普
