Extending the Capture Map Concept to Estimate Discrete and Risk-Based Streamflow Depletion Potential

Area of Science:

• Hydrogeology
• Water Resource Management
• Environmental Modeling

Background:

• Numerical groundwater models are widely used to assess groundwater extraction impacts on surface-water/groundwater exchange.
• Existing
• capture maps
• are deterministic and lack flexibility for analyzing varied extraction scenarios.

Purpose of the Study:

• To generalize the capture map concept for estimating spatially discrete streamflow depletion potential.
• To integrate uncertainty and risk into capture mapping for improved decision-making.
• To develop a stochastic, risk-based framework for groundwater-surface water interactions.

Main Methods:

• Utilized a response matrix to generalize capture map theory.
• Applied first-order, second-moment uncertainty estimation techniques.
• Incorporated "risk shifting" for a stochastic framework.
• Demonstrated the approach with an integrated groundwater/surface-water model of the lower San Antonio River, Texas.

Main Results:

• Developed a generalized method for estimating streamflow depletion potential.
• Quantified uncertainty and risk associated with groundwater extraction impacts.
• Provided a flexible framework for analyzing various extraction scenarios and their effects on streamflow.

Conclusions:

• The generalized capture map approach using response matrices offers a more comprehensive and risk-aware method for assessing groundwater extraction impacts.
• This stochastic framework enhances decision-making for sustainable water resource management.
• The methodology is applicable to complex integrated groundwater-surface water systems.