A quantitative analysis of hydraulic interaction processes in stream-aquifer systems

Area of Science:

• Hydrology
• Hydrogeology
• Environmental Science

Background:

• Stream-aquifer systems exhibit dynamic hydraulic connections.
• Excessive pumping can disrupt these connections, leading to disconnection.
• Understanding disconnection is crucial for sustainable water resource management.

Purpose of the Study:

• To quantitatively analyze the physical processes governing stream-aquifer systems transitioning from connection to disconnection.
• To determine the critical conditions under which hydraulic disconnection occurs.
• To develop an analytical solution for inverted water table movement during disconnection.

Main Methods:

• Utilized a free water table equation to model disconnection.
• Performed theoretical analysis and laboratory experiments.
• Established a boundary-value problem for critical disconnection point movement.

Main Results:

• Identified critical disconnection state: zero horizontal hydraulic gradient and a vertical gradient of 1.
• Derived an analytical solution for inverted water table movement.
• Determined maximum inverted water table thickness equals stream water depth.
• Found maximum hydraulic gradient at streambed center is 2 under steady disconnection.

Conclusions:

• Provides a quantitative understanding of stream-aquifer disconnection processes.
• Offers insights into the physical mechanisms of water flow near streams.
• Aids in accurate assessment of surface water and groundwater resources.