Influence of correlation scale errors on aquifer hydraulic conductivity inversion precision

Abstract

In order to investigate the influence of correlation scale error on the inversion precision of the hydraulic conductivity of the aquifer, the successive linear estimator (SLE) was used to invert the hydraulic conductivity field of a heterogeneous aquifer based on synthetic experiments. By increasing the numbers of observation wells and pumping tests, we analyzed the difference between the estimated and true values of hydraulic conductivity with different correlation scale errors. The relationships between the observation well number and the error in inversion results, and between the pumping test number and the error in inversion results were investigated. The results show that, if the amount of observed head data is insufficient, there will be errors in inversion results with changing correlation scale. Due to the existence of correlation scale error, the improvement of inversion precision gradually slows down with the increase of the amount of observed head data, which indicates that too much observed head data causes data redundancy. Therefore, for the synthetic experiments described in this paper, the observation well number should be less than 41, the pumping test number should be less than 17, and a more suitable method should be selected according to the precision requirements of specific situations in practical engineering.

Keywords

• Hydraulic conductivity
• Parameter inversion
• Successive linear estimator
• Correlation scale error
• Observation well number
• Pumping test number