Assessment of changes in regional groundwater levels through spatio-temporal kriging: application to the southern Basin of Mexico aquifer system

A common approach for calculating the spatial distribution of groundwater level changes consists in choosing a set of different times, interpolating the groundwater level data available at each time over a spatial grid, and then calculating changes in each period by subtracting the interpolated values for these times. However, this can produce misleading results when the data are available in different positions for consecutive times. This paper presents an alternative procedure based on the interpolation of the groundwater level with spatio-temporal kriging, the assessment of the temporal groundwater elevation changes over a regional semiconfined aquifer, and the estimation of their error standard deviations. A comparative analysis of cross-validation results and error standard deviations provides a quantitative measure of the superiority of the introduced approach with respect to the one given in the literature. Moreover, the spatio-temporal case produces more reasonable estimates than the spatial kriging, notably fewer extreme recoveries and drawdowns, in an area under high water stress, such as the upper aquifer of the southern part of the Basin of Mexico aquifer system.