Groundwater quality assessment in two shallow aquifers with different hydrogeological characteristics (case study: Lenjanat and Babol–Amol aquifers in Iran)

Groundwater quality management is based on understanding the spatial distribution of parameters in when assessing the suitability of groundwater for use. In this study, different interpolation methods were evaluated in two shallow aquifers according to their hydrogeological characteristics. After initial data processing, 24 deterministic and geostatistical interpolation methods were used with linear and nonlinear relationships. These included: the inverse distance weighted method; the ordinary kriging; the lognormal ordinary kriging (Log_OK); the universal kriging; the disjunctive kriging; the empirical Bayesian kriging; the simple kriging; natural neighbor; the trend surface; and the Spline methods were compared. The spatial distribution of the total dissolved solids parameter was assessed in the Lenjanat and Babol–Amol shallow aquifers with different hydrogeological characteristics. The seven error criteria were used for verification in cross-validation of all sampling wells. The nonlinear Log_OK method produced better results in the Lenjanat and Babol–Amol aquifers with 57 and 71% of error criteria, respectively. Consequently, the non-linear Log_OK method had promising performance in both shallow aquifers with different hydrogeological characteristics.