Example Discussion Of Aquifer Parameters Calculation Based On Step-head Flow Pumping Test

To improve the precision of the hydrogeological parameters’ calculation deduced from step pumping flow, several new algorithms are proposed on the basis of the traditional ones in this thesis. The traditional one calculated the parameters step by step, while the new one is based on the accumulative steps. By applying to the example, the results under different algorithms were discussed as well as analyzed the applicability, the discrepancy and the sensitivity. Furthermore, this paper propose a once-step algorithm and a twice-step algorithm, introduce the essential principles, compare the result to the original sextic-step, and test its feasibility, to minimize the step of the pumping test with the satisified precision and offer practical advices. The results show that: ⑴After modifying the original data to meet Jacob’s applicability condition, the precision of both the single step algorithm and the accumulative steps algorithm is obviously raised. And the precision is difficult to guarantee without the condition; ⑵The discrepancy between the two algorithms exist to some extent, as well as the discrepancy between different time intervals during the pumping test; ⑶The accumulative steps algorithm has the advantage of lower dispersion degree and smaller residual error, but it is slightly sensitive towards random error, which should be paid more attention in the practical work; ⑷The result of the once-step algorithm is relatively close to the sextic-step results, so the steps of pumping test could be reduced and the project schedule could be shortened to some extent; ⑸The result of the twice-step algorithm is relatively close to the sextic-step results, and the steps of pumping test could be reduced and the project funds could be saved to some extent.