A Physically Based Approach for Estimating Hydraulic Conductivity from HPT Pressure and Flowrate
Robert C Borden1, Ki Young Cha2, Gaisheng Liu3
1North Carolina State University, Campus Box 7908, Raleigh, NC, 27695, USA.
Ground Water
|August 19, 2020
Summary
This study introduces a new equation to calculate hydraulic conductivity using data from the hydraulic profiling tool (HPT). This method improves the accuracy of subsurface characterization for hydrogeology applications.
Area of Science:
- Geosciences
- Hydrogeology
- Environmental Engineering
Background:
- The hydraulic profiling tool (HPT) is a common method for assessing subsurface properties.
- Accurate determination of hydraulic conductivity is crucial for groundwater resource management and contaminant transport studies.
- Existing methods for interpreting HPT data may lack a strong physical basis.
Purpose of the Study:
- To develop a physically based relationship for calculating hydraulic conductivity (K) from HPT measurements.
- To validate the new relationship using field data and compare it with traditional methods.
Main Methods:
- Utilized prior numerical modeling results to establish a correlation between HPT parameters (probe advance rate, diameter, water injection rate, corrected pressure) and hydraulic conductivity.
- Introduced an empirically derived hydraulic efficiency factor (E) into the developed equation.
- Validated the equation using 23 HPT profiles, comparing averaged K values with adjacent slug test results.
Main Results:
- A novel equation was formulated to estimate hydraulic conductivity from HPT data.
- The best-fit value for the hydraulic efficiency factor (E) was determined to be 2.02.
- The developed equation showed good agreement with slug test results, indicating reliable K profile generation.
Conclusions:
- The new equation offers a physically grounded approach for generating hydraulic conductivity profiles using HPT.
- This method enhances the utility of HPT for detailed subsurface hydrological investigations.
- The findings contribute to more accurate site characterization in hydrogeological studies.
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