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磁共振探测(MRS)是目前唯一直接找水的地球物理方法,常被用于估算含水层导水系数.与传统的通过抽水试验获取导水系数值相比,该方法具有低成本及非侵入等优点,但其估算误差较大,准确性有待提升.本文以蒙古国伊和塔拉盆地的MRS为具体实例,通过比较常用计算公式不同参数取值下MRS估算的导水系数与抽水试验计算值的差异,定量探讨了MRS推断含水层深度的准确性、计算公式中关键参数的取值等主要因素对估算结果的影响,并以此为基础在多个环节对原有方法进行了改进.结果显示:(1)MRS推断含水层深度的平均误差为4.85 m,存在随深度增加误差增大的现象.(2)C_P的正确取值是控制误差在合理范围的关键,C_P取最优值,估算的平均误差为15.53%,且其在取值范围内取最大值或最小值,误差均小于原有方法的常用取值.(3)计算公式中关键参数a、b的取值,Seevers公式(a=1、b=2)的估算效果优于Kenyon公式(a=4、b=2).通过比较发现,改进后的方法较原有方法能明显提升估算结果的准确性,具有很好的适用性.
Magnetic Resonance Detection (MRS) is the only geophysical method to find water directly and is often used to estimate the aquifer water conductivity coefficient.Compared with the traditional value obtained by pumping test, this method has low cost and non-invasive But its estimation error is larger and its accuracy needs to be improved.In this paper, the MRS of Iraq and Tara Basin in Mongolia is used as a concrete example to compare the calculated values of water conductivity and pumping test under different parameters , This paper quantitatively explores the influence of MRS on the accuracy of inferring the depth of aquifer and the influence of the main factors such as the value of the key parameters in the formula on the estimation results. Based on this, the original method is improved in many aspects. (2) The correct value of C_P is the key to control error in a reasonable range, C_P takes the optimal value, The estimated average error is 15.53%, and its maximum or minimum value within the range of values, the error is less than the commonly used value of the original method. (3) Calculation formula The key parameters a, b values, Seevers formula (a = 1, b = 2) Kenyon estimate is better than the formula (a = 4, b = 2). By comparison, the improved method than the original method can significantly improve the accuracy of estimates, having good applicability.