Disconnected surface water and groundwater: from theory to practice

Area of Science:

• Hydrogeology
• Environmental Science
• Water Resource Management

Background:

• The term 'disconnected' in river-aquifer systems is often misunderstood.
• There is a lack of definitive literature on disconnected surface water and groundwater systems.
• Historical context and recent advancements in understanding disconnection physics are presented.

Purpose of the Study:

• To close the knowledge gap regarding disconnected surface water and groundwater systems.
• To emphasize the importance of understanding connection states for water management.
• To advocate for robust field methods for identifying disconnection.

Main Methods:

• Review of historical terminology and physics of disconnection.
• Analysis of current field methods for identifying disconnection (infiltration rate independence, unsaturated zone detection).
• Discussion of the implications of groundwater development on disconnected systems.

Main Results:

• Disconnection is identified when stream infiltration is independent of water table position or an unsaturated zone exists.
• Lowering water tables can increase the extent of disconnected stream sections.
• Current methods for identifying disconnection need further development.

Conclusions:

• Accurate identification of surface water-groundwater connection states is fundamental for sustainable water management.
• Further field studies are required to refine disconnection identification methods.
• Heterogeneity and clogging processes significantly impact disconnection and require quantification.