Device and method for utilizing sand launder seepage to simulate coastal zone salt-fresh water abrupt interface

Abstract

The invention discloses a device and method for utilizing sand launder seepage to simulate a coastal zone salt-fresh water abrupt interface. The sand launder at the middle section of the device is fully filled with homogenous fine sand (1), a salt water inlet chamber (7) and a fresh water inlet chamber (9) are arranged at the left end and the right end, overflow baffles (8 and 10) are arranged in the salt water inlet chamber (7) and the fresh water inlet chamber (9) to enable the level of fresh water at the right end to be higher than the level of the salt water at the left end, and a salt water draining hole (11) and a fresh water draining hole (14) are formed in the outer sides of the baffles respectively. The salt water reddened by a red edible coloring agent flows into a salt water inlet hole (12) at the left end in advance, colorless fresh water flows into a fresh water inlet hole (13) at the right end till seepage in the sand launder is stable, the abrupt interface (3) between the red region and the colorless region is observed on the right side, the influence on the position of the salt-fresh water abrupt interface of different salt-fresh water head differences and different salt-fresh water density differences can be simulated, the quantitative relation of the position and a water head or pressure of the interface is established, and change law of the position of the salt-fresh water abrupt interface under different experiment conditions is researched.

Description

1. Technical field [0001] The invention relates to a sand tank seepage simulation device and a simulation method for making a sudden change interface of salty and fresh water in a coastal zone, which can be used to study the hydrodynamic characteristics and changes of groundwater in a coastal zone, and belongs to the technical field of groundwater dynamics in a coastal zone. 2. Background technology [0002] There are long coastlines on land, and coastal areas are usually areas with rapid economic development and dense population. There are underground aquifers distributed in many coastal areas, and the groundwater is discharged into the sea under natural conditions. The underground freshwater resources in coastal aquifers are important water supply sources in coastal areas and become the main target of local development and utilization. Exploitation of underground freshwater resources in coastal aquifers will be threatened by seawater intrusion, which is the main environme...

AI Technical Summary

Problems solved by technology

[0006] Whether it is to study the location of the abrupt change interface of fresh-salt water in the coastal zone, the discharge of fresh groundwater into the sea, or the study of seawater intrusion in the coastal zone and its prevention and control, people often face the following problems: whether there is a sudden change in the salt-salt water in the underground aquifer in the coastal zone interface? Does the location of the brackish-fresh water mutation interface only depend on the phreatic level, or does it depend on both the freshwater head in the freshwater zone and the saltwater head in the brackish zone? Since people are currently unable to directly observe the sudden change interface of salty and fresh water in the coastal zone in the field, even through the observation of the groundwater head, pressure, density, chloride ion or other chemical components in the coastal zone, we can only indirectly understand the salty and fresh water interface. The position, shape and change of water mutation interface

However, these experiments do not observe changes in water head or pressure above and below the brackish-fresh water interface, and the experiments themselves are not based on experimental phenomena or data to propose or verify a new method for determining the position of the brackish-fresh water interface in the coastal zone by using underground freshwater head and saline water head. Therefore, no substantial progress has been made in establishing the theory of the location of the brackish-fresh water interface based on experiments.

Images