Technical NoteOptimal selection of groundwater-level monitoring sites in the Zhangye Basin, Northwest China

•We proposed a new scheme for optimal design groundwater monitoring site.•The kriging, spatial stratification, and temporal stability was integrated.•We examine the temporal stability of groundwater level in Zhangye Basin.•Decreasing expected standard deviation will increase number of observation wells.

SummaryAn optimized groundwater monitoring network is essential for agricultural irrigation that uses groundwater resources. This technical note presents a new scheme to optimize the existing groundwater-level monitoring network in the Zhangye Basin, China. The scheme integrates kriging theory, spatial stratification and temporal stability analysis. The optimized results indicate that the number of additional observation wells in each stratum is correlated with the number of existing wells, the stratum areas and the temporal stability of the groundwater-level spatial pattern. These findings are consistent with expectations. The effectiveness of the proposed method is demonstrated, and its implementation is simple, robust and flexible.