Shallow seawater intrusion prevention and control method based on impermeable geomembrane

Abstract

The invention discloses a shallow seawater intrusion prevention and control method based on an anti-seepage geomembrane. The method comprises the following steps: 1, acquiring hydrogeological data of a shallow aquifer; 2, establishing a shallow aquifer seawater intrusion numerical model, and determining the optimal arrangement depth of the anti-seepage geomembrane; the coastal slope is leveled, and laying of the anti-seepage geomembrane is facilitated; 4, covering an anti-seepage geomembrane along the coast slope, and mounting anti-skid nails at the top end and the bottom end of the geomembrane; and 5, the geomembrane is evenly covered with the cement bag or the gravel, and the balance weight of the geomembrane is increased. From the perspective of controlling the inland fresh water drainage outlet, the arrangement of the anti-seepage geomembrane enables the fresh water drainage outlet to sink, so that the seawater invasion range in the shallow aquifer is limited. Compared with an existing method for preventing and treating seawater invasion, the method is simple in construction arrangement, low in operation cost and convenient to maintain and replace, and has an excellent application prospect.

Description

technical field [0001] The invention relates to a seawater intrusion prevention method, in particular to a shallow seawater intrusion prevention method based on an anti-seepage geomembrane. Background technique [0002] Due to differences in the density of brackish and freshwater, seawater intrudes from the bottom into the freshwater portion of the aquifer, forming an invading saltwater wedge. In its natural state, a dynamic balance is maintained between brackish and fresh water in coastal aquifers. However, when the landside hydraulic gradient decreases (such as water pumping) or the seaside water level increases (such as sea level rise), this dynamic balance will be disrupted, causing the brackish-freshwater interface to move inland, exacerbating the problem of seawater intrusion. [0003] In recent years, due to the destruction of hydrodynamic balance and the rise of sea level caused by excessive exploitation of groundwater, large-scale seawater intrusion has occurred in...

AI Technical Summary

Problems solved by technology

However, due to the problem of gas escape, the gas curtain method is not effective in controlling seawater intrusion in unconfined aquifers, so it is only suitable for confined aquifers with better sealing

In addition, injecting high-pressure gas into the aquifer will introduce a large amount of oxygen into the anoxic aquifer, which will change the physical and chemical environment in the aquifer and pose a threat to the natural ecological balance in the aquifer

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