To develop a simple, accurate, and non-destructive method for estimating the groundwater level (GWL) in an
unconfined sandy aquifer, field measurements of soil electrical resistivity were conducted at the Daqinggou
Ecological Station (DES) in 2005 and the Experimental Base of the Institute of Wind-Sand Land Improvement
and Utilization (IWLIU) in 2009. The resistivity data were acquired through a series of vertical electrical
soundings (VES) using a Wenner array. For comparison with the VES method, the GWLs were also manually
monitored in wells. The results showed that the thirty VES profiles decreased or first increased and then
decreased with increasing electrode spacing (i.e., becoming more conductive with depth). The depth of the
GWL was obtained by calculating the turning points, as inferred from inflections in the apparent resistivity
profiles. The GWL variations between the VES method and manual measurement ranged from 0.22 to
1.03 m at the DES, with a mean value of 0.52 m, and from 0.03 to 0.82 m at the IWLIU, with a mean value
of 0.10 m. The significant differences between the GWLs obtained by the VES method and manual measurement
at the DES were due to the higher GWLs with capillary action; there were no significant differences in
the GWLs obtained at the IWLIU. The linear regression coefficient of determination was 0.97 for the IWLIU
GWL values, indicating a good agreement between the VES method and manual measurements. Therefore,
we conclude that the VES method is a sound measuring tool for estimating GWLs in unconfined sandy aquifers
when the GWL is sufficiently deep (e.g., GWL> 3.98 m).