Function to calculate the derivative of the drawdown with respect to the log of time using the Boulton solution
boulton_solution_dlogt(ptest, a, t0, t1, phi, t)
| ptest | value |
|---|---|
| a | Slope of the straight line fitted to the drawdown data using the Cooper-Jacob approach |
| t0 | Intercept of the straight line fitted to the drawdown data using the Cooper-Jacob approach (early time) |
| t1 | Intercept of the straight line fitted to the drawdown data using the Cooper-Jacob approach (late time) |
| phi | Delay parameter. Dimensionless parameter defined as $$\phi = \frac{\alpha_{1} r^{2} S}{T}$$ where \(\alpha_{1}\) is a fitting parameter without a physical estimation, \(r\) is the distance between the pumping and observation well, \(S\) is the storage coefficient and \(T\) is the transmissivity. |
| t | value |
This function returns
Boulton, N. The drawdown of the water-table under non-steady conditions near a pumped well in an unconfined formation. Proceedings of the Institution of Civil Engineers, 1954, 3, 564-579
Other boulton functions: boulton_WF_LT,
boulton_calculate_parameters,
boulton_solution,
boulton_well_function
data(boulton) ptest <- pumping_test('Well1', Q = 0.03, r = 20, t = boulton$t, s = boulton$s) boulton.sol <- boulton_solution_initial(ptest) boulton.dsol <- boulton_solution_dlogt(ptest, boulton.sol$a, boulton.sol$t0, boulton.sol$t1, boulton.sol$phi, boulton$t)