On the Reliability of Variable‐Rate Pumping Test Results: Sensitivity to Information Content of the Recorded Data
On the Reliability of Variable‐Rate Pumping Test Results: Sensitivity to Information Content of the Recorded Data
复制标题
关于变速泵送测试结果的可靠性：对记录数据信息内容的敏感性
作者：
M. Naderi;H. Gupta
抽水试验被广泛用于估计参数，如渗透率和储存率，使用含水层响应方程，假设时间恒定的抽水率。然而，在实际操作中，排放率通常会不规律地变化，并且随着测试的进行，排放率通常会呈下降趋势。在这种情况下，如果以足够的时间保真度记录放电历史，则可以通过时域分段线性数值积分获得精确的解。然而，如果排放数据不足以表征泵送速率的动态变化，则结果可能是信息丢失，导致推断的参数估计中的偏差。在这里，我们调查了六种选定含水层类型（包括承压含水层、渗漏含水层和非承压含水层）的问题的严重性。我们的研究结果表明，由于时间分辨率不足的放电数据和系统的观测误差的信息损失的影响是显着更严重的比由于随机观测误差。这意味着操作员应共同努力，在整个测试期间以最高的实际时间分辨率记录泵送速率。
Pumping tests are widely used to estimate parameters such as transmissivity and storativity, using aquifer response equations that assume a time‐constant pumping rate. However, in actual practice the discharge rate will often vary erratically and follow a generally decreasing trend as the test proceeds. In such cases, if the discharge history is recorded with sufficient temporal fidelity, accurate solutions can be obtained via time domain piecewise‐linear numerical integration. However, if the discharge data do not adequately characterize the variability in the dynamics of the pumping rate, the result can be information loss leading to bias in the inferred parameter estimates. Here, we investigate the severity of this problem for six selected aquifer types, including those that are confined, leaky, and unconfined. Our results indicate that the effects of information loss due to inadequate temporal resolution of the discharge data and systematic observational error are significantly more severe than due to random observational error. The implication is that operators should make a concerted effort to record the pumping rate at the highest practical temporal resolution throughout the duration of the test.