What Is the Cooper-Jacob Aquifer Drawdown & Pumping Test Calculator?
Calculate late-time aquifer pumping drawdown, slope per log cycle Δs, Theis parameter u, and zero-drawdown time intercept t0 using the Cooper-Jacob method.
The Cooper-Jacob Aquifer Drawdown & Pumping Test Calculator is an analytical tool in the construction domain designed to evaluate Aquifer Transmissivity (T), Storativity (S), Pumping Rate (Q), Observation Distance (r), Pumping Duration using verified mathematical equations. It provides reproducible, deterministic calculations for academic, professional, and practical applications.
How Does the Cooper-Jacob Aquifer Drawdown & Pumping Test Calculator Work?
This calculator computes results by taking input values for Aquifer Transmissivity (T), Storativity (S), Pumping Rate (Q), Observation Distance (r), Pumping Duration and applying the governing equation: Cooper-Jacob logarithmic expansion of the Theis well equation valid for dimensionless parameter u < 0.05.. Values are checked for dimensional consistency and processed through standard arithmetic routines.
Cooper-Jacob Aquifer Drawdown & Pumping Test Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Cooper-Jacob logarithmic expansion of the Theis well equation valid for dimensionless parameter u < 0.05.
How to Use the Cooper-Jacob Aquifer Drawdown & Pumping Test Calculator
- Enter your value for Aquifer Transmissivity (T) in m²/day.
- Enter your value for Storativity (S).
- Enter your value for Pumping Rate (Q) in m³/day.
- Enter your value for Observation Distance (r) in m.
- Enter your value for Pumping Duration in hours.
- Verify your input parameters to ensure they match your design or problem specifications.
- Review the calculated results, intermediate mathematical steps, and graphical visualization below.
Step-by-Step Example Calculation
Observation Piezometer (r = 50m, t = 48h, Q = 2000 m³/day)
Input Values:
Understanding Your Result
The calculated output gives the primary solution for Cooper-Jacob Aquifer Drawdown & Pumping Test under the specified conditions. Use this value to compare against standard design tolerances, benchmarks, or reference ranges in construction.
Factors That Affect the Result
- Input precision and measurement accuracy of Aquifer Transmissivity (T), Storativity (S), Pumping Rate (Q), Observation Distance (r), Pumping Duration.
- Operating conditions, environmental parameters, and specific construction tolerances.
- Boundary constraints and deviations from nominal theoretical model assumptions.
When Should You Use This Calculator?
- When performing technical analysis or dimensioning related to Cooper-Jacob Aquifer Drawdown & Pumping Test.
- To cross-verify manual calculations or theoretical models in construction.
- For preliminary estimates before conducting detailed field measurements or laboratory testing.
Assumptions & Limitations
- The Cooper-Jacob approximation introduces less than 1% error when u < 0.01 and less than 5% error when u < 0.05.
- For early-time data (u > 0.05), the full Theis curve matching method W(u) must be utilized.
Frequently Asked Questions
What is Δs in the Cooper-Jacob method?+
How do you determine storativity S from field data?+
Calculation Accuracy & Reference Note
This calculator implements verified mathematical formulas for Cooper-Jacob Aquifer Drawdown & Pumping Test Calculator. Always verify critical results against official domain standards and manufacturer documentation.