Hydrogeochemical Evolution of Interaction Between Surface Water and Groundwater Affected by Exploitation

Area of Science:

• Hydrogeology
• Environmental Chemistry
• Water Resource Management

Background:

• Understanding hydrogeochemical evolution is vital for ensuring water supply quality in riverside areas.
• Groundwater exploitation significantly impacts the interactions between surface and groundwater.

Purpose of the Study:

• To investigate the seasonal and spatial hydrogeochemical evolution in the Hulan water source area.
• To assess the effects of groundwater exploitation on water chemistry and surface-groundwater interactions.

Main Methods:

• Hydrochemical analyses were performed to determine major ion concentrations and total dissolved solids (TDS).
• Stable isotope tracers were employed to track water origins and mixing patterns.
• Seasonal and spatial variations were analyzed along typical infiltration paths.

Main Results:

• Major ion and TDS concentrations increased significantly during the dry season.
• Surface water proportions along infiltration paths increased from 8%-63% (wet season) to 11%-84% (dry season) due to exploitation.
• Two distinct zones were identified: an intensive mixing zone and an exploitation influence zone with elevated ion concentrations.

Conclusions:

• Groundwater exploitation enhances surface water infiltration, particularly during dry seasons, leading to altered hydrogeochemistry.
• Water-rock interactions, evaporation, and mixing effects contribute to increased ion concentrations in the exploitation influence zone.
• Management strategies are needed to mitigate the impacts of exploitation on water quality in riverside source areas.