Estimating hydrogeological parameters at groundwater level observation wells without pumping well information

• Published in: Journal of hydrology (Amsterdam) Vol. 624; p. 129873
• Main Authors: Yu, Hwa-Lung, Lee, Shih-Yao, Tseng, Hua-Ting, Lin, Ying-Fan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2023
• Subjects: Aquifer pumping test; Confined aquifer; Impulse response function; Parameter estimation; Transfer function modeling; Confined aquifer; Aquifer pumping test; Transfer function modeling; Parameter estimation; Impulse response function
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/j.jhydrol.2023.129873

Aquifer pumping is a common method of meeting human water needs, but it can also disrupt the natural flow of groundwater and cause fluctuations in groundwater levels. These fluctuations, however, can provide useful insights into hydrogeological properties when measured in an observation well. Traditional modeling methods are not well suited for analyzing such data because they lack essential details about the pumping wells, such as their number, distance from the observation well, and pumping rates. To address this issue, new impulse response function for transfer function modeling is developed that accurately describes the confined flow in such situations. The proposed function is based on the Theis solution, which uniformly distributes the effects of multiple pumping wells within a circular area around the observation well. This allows our function to accurately estimate hydrogeological parameters and pumping rates without knowing the number and specific location of pumping wells. The effects of well distance, spatial arrangement, and aquifer anisotropy on the accuracy of our function are also analyzed using synthetic experiments and Morris sensitivity analysis. The results show that the proposed function is effective in estimating essential hydrogeological parameters, such as the aquifer storativity, using only drawdown time series data from a observation well. [Display omitted] The figure of the graphical abstract illustrates that the variation of the drawdown measured in an observation well responds to pumping with unknown distances and pumping rate. We present a new drawdown solution derived from an impulse response function based on the Theis solution, permitting the process of parameter estimation to work without knowing the pumping well information. •Pumping pattern from human activities can be extracted from observation data.•Analyzing extracted data to estimate hydraulic parameters, pumping rate.•Parameter estimation solution developed without well infomation requirement.•Proposed solution integrates into transfer function-noise model.